diff --git a/unix/gtkcompat.h b/unix/gtkcompat.h
index 43a3181c..c0341c34 100644
--- a/unix/gtkcompat.h
+++ b/unix/gtkcompat.h
@@ -177,6 +177,10 @@
 
 #endif /* 2.24 */
 
+#if !GTK_CHECK_VERSION(3,0,0)
+#define GDK_IS_X11_WINDOW(window) (1)
+#endif
+
 #if GTK_CHECK_VERSION(3,0,0)
 #define STANDARD_OK_LABEL "_OK"
 #define STANDARD_OPEN_LABEL "_Open"
diff --git a/unix/gtkdlg.c b/unix/gtkdlg.c
index 119c428c..737163f2 100644
--- a/unix/gtkdlg.c
+++ b/unix/gtkdlg.c
@@ -24,6 +24,7 @@
 #include <gdk/gdkx.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
+#include "x11misc.h"
 #endif
 
 #ifdef TESTMODE
@@ -1776,9 +1777,12 @@ static void filefont_clicked(GtkButton *button, gpointer data)
             GdkFont *font = gdk_font_load(fontname);
             if (font) {
                 XFontStruct *xfs = GDK_FONT_XFONT(font);
-                Display *disp = GDK_FONT_XDISPLAY(font);
+                Display *disp = get_x11_display();
                 Atom fontprop = XInternAtom(disp, "FONT", False);
                 unsigned long ret;
+
+                assert(disp); /* this is GTK1! */
+
 		gdk_font_ref(font);
                 if (XGetFontProperty(xfs, fontprop, &ret)) {
                     char *name = XGetAtomName(disp, (Atom)ret);
diff --git a/unix/gtkfont.c b/unix/gtkfont.c
index bb4c709a..4dd7919c 100644
--- a/unix/gtkfont.c
+++ b/unix/gtkfont.c
@@ -31,6 +31,7 @@
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/Xatom.h>
+#include "x11misc.h"
 #endif
 
 /*
@@ -177,6 +178,11 @@ typedef struct x11font_individual {
 
 struct x11font {
     struct unifont u;
+    /*
+     * Copy of the X display handle, so we don't have to keep
+     * extracting it from GDK.
+     */
+    Display *disp;
     /*
      * Individual physical X fonts. We store a number of these, for
      * automatically guessed bold and wide variants.
@@ -308,9 +314,9 @@ static char *xlfd_recompose(const struct xlfd_decomposed *dec)
 #undef ARG_INT
 }
 
-static char *x11_guess_derived_font_name(XFontStruct *xfs, int bold, int wide)
+static char *x11_guess_derived_font_name(Display *disp, XFontStruct *xfs,
+                                         int bold, int wide)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
     Atom fontprop = XInternAtom(disp, "FONT", False);
     unsigned long ret;
     if (XGetFontProperty(xfs, fontprop, &ret)) {
@@ -428,12 +434,15 @@ static unifont *x11font_create(GtkWidget *widget, const char *name,
 {
     struct x11font *xfont;
     XFontStruct *xfs;
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
+    Display *disp;
     Atom charset_registry, charset_encoding, spacing;
     unsigned long registry_ret, encoding_ret, spacing_ret;
     int pubcs, realcs, sixteen_bit, variable;
     int i;
 
+    if ((disp = get_x11_display()) == NULL)
+        return NULL;
+
     xfs = XLoadQueryFont(disp, name);
     if (!xfs)
 	return NULL;
@@ -508,6 +517,7 @@ static unifont *x11font_create(GtkWidget *widget, const char *name,
 #else
 #error No drawtype available at all
 #endif
+    xfont->disp = disp;
     xfont->real_charset = realcs;
     xfont->sixteen_bit = sixteen_bit;
     xfont->variable = variable;
@@ -534,8 +544,8 @@ static unifont *x11font_create(GtkWidget *widget, const char *name,
 
 static void x11font_destroy(unifont *font)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
     struct x11font *xfont = (struct x11font *)font;
+    Display *disp = xfont->disp;
     int i;
 
     for (i = 0; i < lenof(xfont->fonts); i++) {
@@ -561,9 +571,9 @@ static void x11font_destroy(unifont *font)
 
 static void x11_alloc_subfont(struct x11font *xfont, int sfid)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
+    Display *disp = xfont->disp;
     char *derived_name = x11_guess_derived_font_name
-	(xfont->fonts[0].xfs, sfid & 1, !!(sfid & 2));
+	(disp, xfont->fonts[0].xfs, sfid & 1, !!(sfid & 2));
     xfont->fonts[sfid].xfs = XLoadQueryFont(disp, derived_name);
     xfont->fonts[sfid].allocated = TRUE;
     sfree(derived_name);
@@ -618,27 +628,25 @@ static int x11font_width_8(unifont_drawctx *ctx, x11font_individual *xfi,
 }
 
 #ifdef DRAW_TEXT_GDK
-static void x11font_gdk_setup(unifont_drawctx *ctx, x11font_individual *xfi)
+static void x11font_gdk_setup(unifont_drawctx *ctx, x11font_individual *xfi,
+                              Display *disp)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
     XSetFont(disp, GDK_GC_XGC(ctx->u.gdk.gc), xfi->xfs->fid);
 }
 
-static void x11font_gdk_draw_16(unifont_drawctx *ctx,
-                                x11font_individual *xfi, int x, int y,
+static void x11font_gdk_draw_16(unifont_drawctx *ctx, x11font_individual *xfi,
+                                Display *disp, int x, int y,
                                 const void *vstring, int start, int length)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
     const XChar2b *string = (const XChar2b *)vstring;
     XDrawString16(disp, GDK_DRAWABLE_XID(ctx->u.gdk.target),
                   GDK_GC_XGC(ctx->u.gdk.gc), x, y, string+start, length);
 }
 
-static void x11font_gdk_draw_8(unifont_drawctx *ctx,
-                               x11font_individual *xfi, int x, int y,
+static void x11font_gdk_draw_8(unifont_drawctx *ctx, x11font_individual *xfi,
+                               Display *disp, int x, int y,
                                const void *vstring, int start, int length)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
     const char *string = (const char *)vstring;
     XDrawString(disp, GDK_DRAWABLE_XID(ctx->u.gdk.target),
                 GDK_GC_XGC(ctx->u.gdk.gc), x, y, string+start, length);
@@ -646,10 +654,10 @@ static void x11font_gdk_draw_8(unifont_drawctx *ctx,
 #endif
 
 #ifdef DRAW_TEXT_CAIRO
-static void x11font_cairo_setup(unifont_drawctx *ctx, x11font_individual *xfi)
+static void x11font_cairo_setup(
+    unifont_drawctx *ctx, x11font_individual *xfi, Display *disp)
 {
     if (xfi->pixmap == None) {
-        Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
         XGCValues gcvals;
         GdkWindow *widgetwin = gtk_widget_get_window(ctx->u.cairo.widget);
         int widgetscr = GDK_SCREEN_XNUMBER(gdk_window_get_screen(widgetwin));
@@ -693,12 +701,12 @@ static void x11font_cairo_setup(unifont_drawctx *ctx, x11font_individual *xfi)
     }
 }
 
-static void x11font_cairo_cache_glyph(x11font_individual *xfi, int glyphindex)
+static void x11font_cairo_cache_glyph(
+    Display *disp, x11font_individual *xfi, int glyphindex)
 {
     XImage *image;
     int x, y;
     unsigned char *bitmap;
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
     const XCharStruct *xcs = x11_char_struct(xfi->xfs, glyphindex >> 8,
                                              glyphindex & 0xFF);
 
@@ -752,11 +760,10 @@ static void x11font_cairo_draw_glyph(unifont_drawctx *ctx,
     }
 }
 
-static void x11font_cairo_draw_16(unifont_drawctx *ctx,
-                                  x11font_individual *xfi, int x, int y,
-                                  const void *vstring, int start, int length)
+static void x11font_cairo_draw_16(
+    unifont_drawctx *ctx, x11font_individual *xfi, Display *disp,
+    int x, int y, const void *vstring, int start, int length)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
     const XChar2b *string = (const XChar2b *)vstring + start;
     int i;
     for (i = 0; i < length; i++) {
@@ -768,7 +775,7 @@ static void x11font_cairo_draw_16(unifont_drawctx *ctx,
                 XDrawImageString16(disp, xfi->pixmap, xfi->gc,
                                    xfi->pixoriginx, xfi->pixoriginy,
                                    string+i, 1);
-                x11font_cairo_cache_glyph(xfi, glyphindex);
+                x11font_cairo_cache_glyph(disp, xfi, glyphindex);
             }
             x11font_cairo_draw_glyph(ctx, xfi, x, y, glyphindex);
             x += XTextWidth16(xfi->xfs, string+i, 1);
@@ -776,11 +783,10 @@ static void x11font_cairo_draw_16(unifont_drawctx *ctx,
     }
 }
 
-static void x11font_cairo_draw_8(unifont_drawctx *ctx,
-                                 x11font_individual *xfi, int x, int y,
-                                 const void *vstring, int start, int length)
+static void x11font_cairo_draw_8(
+    unifont_drawctx *ctx, x11font_individual *xfi, Display *disp,
+    int x, int y, const void *vstring, int start, int length)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
     const char *string = (const char *)vstring + start;
     int i;
     for (i = 0; i < length; i++) {
@@ -791,7 +797,7 @@ static void x11font_cairo_draw_8(unifont_drawctx *ctx,
                 XDrawImageString(disp, xfi->pixmap, xfi->gc,
                                  xfi->pixoriginx, xfi->pixoriginy,
                                  string+i, 1);
-                x11font_cairo_cache_glyph(xfi, glyphindex);
+                x11font_cairo_cache_glyph(disp, xfi, glyphindex);
             }
             x11font_cairo_draw_glyph(ctx, xfi, x, y, glyphindex);
             x += XTextWidth(xfi->xfs, string+i, 1);
@@ -803,9 +809,10 @@ static void x11font_cairo_draw_8(unifont_drawctx *ctx,
 struct x11font_drawfuncs {
     int (*width)(unifont_drawctx *ctx, x11font_individual *xfi,
                  const void *vstring, int start, int length);
-    void (*setup)(unifont_drawctx *ctx, x11font_individual *xfi);
-    void (*draw)(unifont_drawctx *ctx, x11font_individual *xfi, int x, int y,
-                 const void *vstring, int start, int length);
+    void (*setup)(unifont_drawctx *ctx, x11font_individual *xfi,
+                  Display *disp);
+    void (*draw)(unifont_drawctx *ctx, x11font_individual *xfi, Display *disp,
+                 int x, int y, const void *vstring, int start, int length);
 };
 
 /*
@@ -843,12 +850,11 @@ static const struct x11font_drawfuncs x11font_drawfuncs[2*DRAWTYPE_NTYPES] = {
 #endif
 };
 
-static void x11font_really_draw_text(const struct x11font_drawfuncs *dfns,
-                                     unifont_drawctx *ctx,
-                                     x11font_individual *xfi, int x, int y,
-                                     const void *string, int nchars,
-                                     int shadowoffset,
-                                     int fontvariable, int cellwidth)
+static void x11font_really_draw_text(
+    const struct x11font_drawfuncs *dfns, unifont_drawctx *ctx,
+    x11font_individual *xfi, Display *disp,
+    int x, int y, const void *string, int nchars,
+    int shadowoffset, int fontvariable, int cellwidth)
 {
     int start = 0, step, nsteps, centre;
 
@@ -869,16 +875,17 @@ static void x11font_really_draw_text(const struct x11font_drawfuncs *dfns,
         centre = FALSE;
     }
 
-    dfns->setup(ctx, xfi);
+    dfns->setup(ctx, xfi, disp);
 
     while (nsteps-- > 0) {
 	int X = x;
 	if (centre)
 	    X += (cellwidth - dfns->width(ctx, xfi, string, start, step)) / 2;
 
-        dfns->draw(ctx, xfi, X, y, string, start, step);
+        dfns->draw(ctx, xfi, disp, X, y, string, start, step);
 	if (shadowoffset)
-            dfns->draw(ctx, xfi, X + shadowoffset, y, string, start, step);
+            dfns->draw(ctx, xfi, disp, X + shadowoffset, y,
+                       string, start, step);
 
 	x += cellwidth;
         start += step;
@@ -935,7 +942,7 @@ static void x11font_draw_text(unifont_drawctx *ctx, unifont *font,
 	}
 
 	x11font_really_draw_text(x11font_drawfuncs + index + 1, ctx,
-                                 &xfont->fonts[sfid], x, y,
+                                 &xfont->fonts[sfid], xfont->disp, x, y,
                                  xcs, len, shadowoffset,
                                  xfont->variable, cellwidth * mult);
 	sfree(xcs);
@@ -948,7 +955,7 @@ static void x11font_draw_text(unifont_drawctx *ctx, unifont *font,
         int sblen = wc_to_mb(xfont->real_charset, 0, string, len,
                              sbstring, len+1, ".", NULL, NULL);
 	x11font_really_draw_text(x11font_drawfuncs + index + 0, ctx,
-                                 &xfont->fonts[sfid], x, y,
+                                 &xfont->fonts[sfid], xfont->disp, x, y,
 				 sbstring, sblen, shadowoffset,
 				 xfont->variable, cellwidth * mult);
         sfree(sbstring);
@@ -972,11 +979,14 @@ static void x11font_draw_combining(unifont_drawctx *ctx, unifont *font,
 static void x11font_enum_fonts(GtkWidget *widget,
 			       fontsel_add_entry callback, void *callback_ctx)
 {
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
+    Display *disp;
     char **fontnames;
     char *tmp = NULL;
     int nnames, i, max, tmpsize;
 
+    if ((disp = get_x11_display()) == NULL)
+        return;
+
     max = 32768;
     while (1) {
 	fontnames = XListFonts(disp, "*", max, &nnames);
@@ -1145,10 +1155,13 @@ static char *x11font_canonify_fontname(GtkWidget *widget, const char *name,
      * selector treats them as worthwhile in their own right.
      */
     XFontStruct *xfs;
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
+    Display *disp;
     Atom fontprop, fontprop2;
     unsigned long ret;
 
+    if ((disp = get_x11_display()) == NULL)
+        return NULL;
+
     xfs = XLoadQueryFont(disp, name);
 
     if (!xfs)
@@ -1191,7 +1204,7 @@ static char *x11font_scale_fontname(GtkWidget *widget, const char *name,
 static char *x11font_size_increment(unifont *font, int increment)
 {
     struct x11font *xfont = (struct x11font *)font;
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
+    Display *disp = xfont->disp;
     Atom fontprop = XInternAtom(disp, "FONT", False);
     char *returned_name = NULL;
     unsigned long ret;
diff --git a/unix/gtkmain.c b/unix/gtkmain.c
index 67581604..8136676e 100644
--- a/unix/gtkmain.c
+++ b/unix/gtkmain.c
@@ -41,6 +41,7 @@
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/Xatom.h>
+#include "x11misc.h"
 #endif
 
 static char *progname, **gtkargvstart;
@@ -54,8 +55,10 @@ static const char *app_name = "pterm";
 char *x_get_default(const char *key)
 {
 #ifndef NOT_X_WINDOWS
-    return XGetDefault(GDK_DISPLAY_XDISPLAY(gdk_display_get_default()),
-                       app_name, key);
+    Display *disp;
+    if ((disp = get_x11_display()) == NULL)
+        return NULL;
+    return XGetDefault(disp, app_name, key);
 #else
     return NULL;
 #endif
diff --git a/unix/gtkmisc.c b/unix/gtkmisc.c
index 23f26d07..e9fcaa75 100644
--- a/unix/gtkmisc.c
+++ b/unix/gtkmisc.c
@@ -15,6 +15,11 @@
 #include "putty.h"
 #include "gtkcompat.h"
 
+#ifndef NOT_X_WINDOWS
+#include <gdk/gdkx.h>
+#include <X11/Xlib.h>
+#endif
+
 void get_label_text_dimensions(const char *text, int *width, int *height)
 {
     /*
@@ -206,3 +211,14 @@ char *buildinfo_gtk_version(void)
     return dupprintf("%d.%d.%d",
                      GTK_MAJOR_VERSION, GTK_MINOR_VERSION, GTK_MICRO_VERSION);
 }
+
+#ifndef NOT_X_WINDOWS
+Display *get_x11_display(void)
+{
+#if GTK_CHECK_VERSION(3,0,0)
+    if (!GDK_IS_X11_DISPLAY(gdk_display_get_default()))
+        return NULL;
+#endif
+    return GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
+}
+#endif
diff --git a/unix/gtkwin.c b/unix/gtkwin.c
index b058db27..640b4b15 100644
--- a/unix/gtkwin.c
+++ b/unix/gtkwin.c
@@ -97,6 +97,9 @@ struct gui_data {
     GtkWidget *menu, *specialsmenu, *specialsitem1, *specialsitem2,
 	*restartitem;
     GtkWidget *sessionsmenu;
+#ifndef NOT_X_WINDOWS
+    Display *disp;
+#endif
 #ifndef NO_BACKING_PIXMAPS
     /*
      * Server-side pixmap which we use to cache the terminal window's
@@ -2854,31 +2857,36 @@ void frontend_request_paste(void *frontend, int clipboard)
  */
 
 /* Store the data in a cut-buffer. */
-static void store_cutbuffer(char * ptr, int len)
+static void store_cutbuffer(struct gui_data *inst, char *ptr, int len)
 {
 #ifndef NOT_X_WINDOWS
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
-    /* ICCCM says we must rotate the buffers before storing to buffer 0. */
-    XRotateBuffers(disp, 1);
-    XStoreBytes(disp, ptr, len);
+    if (inst->disp) {
+        /* ICCCM says we must rotate the buffers before storing to buffer 0. */
+        XRotateBuffers(inst->disp, 1);
+        XStoreBytes(inst->disp, ptr, len);
+    }
 #endif
 }
 
 /* Retrieve data from a cut-buffer.
  * Returned data needs to be freed with XFree().
  */
-static char *retrieve_cutbuffer(int *nbytes)
+static char *retrieve_cutbuffer(struct gui_data *inst, int *nbytes)
 {
 #ifndef NOT_X_WINDOWS
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
-    char * ptr;
-    ptr = XFetchBytes(disp, nbytes);
+    char *ptr;
+    if (!inst->disp) {
+        *nbytes = 0;
+        return NULL;
+    }
+    ptr = XFetchBytes(inst->disp, nbytes);
     if (*nbytes <= 0 && ptr != 0) {
 	XFree(ptr);
 	ptr = 0;
     }
     return ptr;
 #else
+    *nbytes = 0;
     return NULL;
 #endif
 }
@@ -2907,7 +2915,6 @@ void write_clip(void *frontend, int clipboard,
 #ifndef NOT_X_WINDOWS
 	XTextProperty tp;
 	char *list[1];
-        Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
 #endif
 
 	state->pasteout_data_utf8 = snewn(len*6, char);
@@ -2931,8 +2938,8 @@ void write_clip(void *frontend, int clipboard,
 	 */
 #ifndef NOT_X_WINDOWS
 	list[0] = state->pasteout_data_utf8;
-	if (Xutf8TextListToTextProperty(disp, list, 1,
-					XCompoundTextStyle, &tp) == 0) {
+	if (inst->disp && Xutf8TextListToTextProperty(
+                inst->disp, list, 1, XCompoundTextStyle, &tp) == 0) {
 	    state->pasteout_data_ctext = snewn(tp.nitems+1, char);
 	    memcpy(state->pasteout_data_ctext, tp.value, tp.nitems);
 	    state->pasteout_data_ctext_len = tp.nitems;
@@ -2966,7 +2973,7 @@ void write_clip(void *frontend, int clipboard,
 
     /* The legacy X cut buffers go with PRIMARY, not any other clipboard */
     if (state->atom == GDK_SELECTION_PRIMARY)
-        store_cutbuffer(state->pasteout_data, state->pasteout_data_len);
+        store_cutbuffer(inst, state->pasteout_data, state->pasteout_data_len);
 
     if (gtk_selection_owner_set(inst->area, state->atom,
 				inst->input_event_time)) {
@@ -3131,7 +3138,7 @@ static void selection_received(GtkWidget *widget, GtkSelectionData *seldata,
      */
     if (seldata_length <= 0) {
 #ifndef NOT_X_WINDOWS
-	text = retrieve_cutbuffer(&length);
+	text = retrieve_cutbuffer(inst, &length);
 	if (length == 0)
 	    return;
 	/* Xterm is rumoured to expect Latin-1, though I havn't checked the
@@ -3149,13 +3156,13 @@ static void selection_received(GtkWidget *widget, GtkSelectionData *seldata,
 #ifndef NOT_X_WINDOWS
             XTextProperty tp;
             int ret, count;
-            Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
 
 	    tp.value = (unsigned char *)seldata_data;
 	    tp.encoding = (Atom) seldata_type;
 	    tp.format = gtk_selection_data_get_format(seldata);
 	    tp.nitems = seldata_length;
-	    ret = Xutf8TextPropertyToTextList(disp, &tp, &list, &count);
+	    ret = inst->disp == NULL ? -1 :
+                Xutf8TextPropertyToTextList(inst->disp, &tp, &list, &count);
 	    if (ret == 0 && count == 1) {
                 text = list[0];
                 length = strlen(list[0]);
@@ -3220,32 +3227,33 @@ void init_clipboard(struct gui_data *inst)
      * Ensure that all the cut buffers exist - according to the ICCCM,
      * we must do this before we start using cut buffers.
      */
-    unsigned char empty[] = "";
-    Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
-    x11_ignore_error(disp, BadMatch);
-    XChangeProperty(disp, GDK_ROOT_WINDOW(),
-		    XA_CUT_BUFFER0, XA_STRING, 8, PropModeAppend, empty, 0);
-    x11_ignore_error(disp, BadMatch);
-    XChangeProperty(disp, GDK_ROOT_WINDOW(),
-		    XA_CUT_BUFFER1, XA_STRING, 8, PropModeAppend, empty, 0);
-    x11_ignore_error(disp, BadMatch);
-    XChangeProperty(disp, GDK_ROOT_WINDOW(),
-		    XA_CUT_BUFFER2, XA_STRING, 8, PropModeAppend, empty, 0);
-    x11_ignore_error(disp, BadMatch);
-    XChangeProperty(disp, GDK_ROOT_WINDOW(),
-		    XA_CUT_BUFFER3, XA_STRING, 8, PropModeAppend, empty, 0);
-    x11_ignore_error(disp, BadMatch);
-    XChangeProperty(disp, GDK_ROOT_WINDOW(),
-		    XA_CUT_BUFFER4, XA_STRING, 8, PropModeAppend, empty, 0);
-    x11_ignore_error(disp, BadMatch);
-    XChangeProperty(disp, GDK_ROOT_WINDOW(),
-		    XA_CUT_BUFFER5, XA_STRING, 8, PropModeAppend, empty, 0);
-    x11_ignore_error(disp, BadMatch);
-    XChangeProperty(disp, GDK_ROOT_WINDOW(),
-		    XA_CUT_BUFFER6, XA_STRING, 8, PropModeAppend, empty, 0);
-    x11_ignore_error(disp, BadMatch);
-    XChangeProperty(disp, GDK_ROOT_WINDOW(),
-		    XA_CUT_BUFFER7, XA_STRING, 8, PropModeAppend, empty, 0);
+    if (inst->disp) {
+        unsigned char empty[] = "";
+        x11_ignore_error(inst->disp, BadMatch);
+        XChangeProperty(inst->disp, GDK_ROOT_WINDOW(), XA_CUT_BUFFER0,
+                        XA_STRING, 8, PropModeAppend, empty, 0);
+        x11_ignore_error(inst->disp, BadMatch);
+        XChangeProperty(inst->disp, GDK_ROOT_WINDOW(), XA_CUT_BUFFER1,
+                        XA_STRING, 8, PropModeAppend, empty, 0);
+        x11_ignore_error(inst->disp, BadMatch);
+        XChangeProperty(inst->disp, GDK_ROOT_WINDOW(), XA_CUT_BUFFER2,
+                        XA_STRING, 8, PropModeAppend, empty, 0);
+        x11_ignore_error(inst->disp, BadMatch);
+        XChangeProperty(inst->disp, GDK_ROOT_WINDOW(), XA_CUT_BUFFER3,
+                        XA_STRING, 8, PropModeAppend, empty, 0);
+        x11_ignore_error(inst->disp, BadMatch);
+        XChangeProperty(inst->disp, GDK_ROOT_WINDOW(), XA_CUT_BUFFER4,
+                        XA_STRING, 8, PropModeAppend, empty, 0);
+        x11_ignore_error(inst->disp, BadMatch);
+        XChangeProperty(inst->disp, GDK_ROOT_WINDOW(), XA_CUT_BUFFER5,
+                        XA_STRING, 8, PropModeAppend, empty, 0);
+        x11_ignore_error(inst->disp, BadMatch);
+        XChangeProperty(inst->disp, GDK_ROOT_WINDOW(), XA_CUT_BUFFER6,
+                        XA_STRING, 8, PropModeAppend, empty, 0);
+        x11_ignore_error(inst->disp, BadMatch);
+        XChangeProperty(inst->disp, GDK_ROOT_WINDOW(), XA_CUT_BUFFER7,
+                        XA_STRING, 8, PropModeAppend, empty, 0);
+    }
 #endif
 
     inst->clipstates[CLIP_PRIMARY].atom = GDK_SELECTION_PRIMARY;
@@ -4060,10 +4068,14 @@ const char *get_x_display(void *frontend)
 }
 
 #ifndef NOT_X_WINDOWS
-long get_windowid(void *frontend)
+int get_windowid(void *frontend, long *id)
 {
     struct gui_data *inst = (struct gui_data *)frontend;
-    return (long)GDK_WINDOW_XID(gtk_widget_get_window(inst->area));
+    GdkWindow *window = gtk_widget_get_window(inst->area);
+    if (!GDK_IS_X11_WINDOW(window))
+        return FALSE;
+    *id = GDK_WINDOW_XID(window);
+    return TRUE;
 }
 #endif
 
@@ -4992,6 +5004,7 @@ void new_session_window(Conf *conf, const char *geometry_string)
 #endif
 
 #ifndef NOT_X_WINDOWS
+    inst->disp = get_x11_display();
     if (geometry_string) {
         int flags, x, y;
         unsigned int w, h;
@@ -5046,13 +5059,11 @@ void new_session_window(Conf *conf, const char *geometry_string)
             GdkWindow *gdkwin;
             gtk_widget_realize(GTK_WIDGET(inst->window));
             gdkwin = gtk_widget_get_window(GTK_WIDGET(inst->window));
-            if (gdk_window_ensure_native(gdkwin)) {
-                Display *disp =
-                    GDK_DISPLAY_XDISPLAY(gdk_window_get_display(gdkwin));
+            if (inst->disp && gdk_window_ensure_native(gdkwin)) {
                 XClassHint *xch = XAllocClassHint();
                 xch->res_name = (char *)winclass;
                 xch->res_class = (char *)winclass;
-                XSetClassHint(disp, GDK_WINDOW_XID(gdkwin), xch);
+                XSetClassHint(inst->disp, GDK_WINDOW_XID(gdkwin), xch);
                 XFree(xch);
             }
 #endif
diff --git a/unix/unix.h b/unix/unix.h
index e6609aa9..a6dcaca0 100644
--- a/unix/unix.h
+++ b/unix/unix.h
@@ -195,7 +195,7 @@ void app_menu_action(void *frontend, enum MenuAction);
 /* Things pty.c needs from pterm.c */
 const char *get_x_display(void *frontend);
 int font_dimension(void *frontend, int which);/* 0 for width, 1 for height */
-long get_windowid(void *frontend);
+int get_windowid(void *frontend, long *id);
 
 /* Things gtkdlg.c needs from pterm.c */
 #ifdef MAY_REFER_TO_GTK_IN_HEADERS
diff --git a/unix/uxpty.c b/unix/uxpty.c
index 4387ad8f..a6069ce6 100644
--- a/unix/uxpty.c
+++ b/unix/uxpty.c
@@ -742,6 +742,7 @@ static const char *pty_init(void *frontend, void **backend_handle, Conf *conf,
     int slavefd;
     pid_t pid, pgrp;
 #ifndef NOT_X_WINDOWS		       /* for Mac OS X native compilation */
+    int got_windowid;
     long windowid;
 #endif
     Pty pty;
@@ -794,7 +795,7 @@ static const char *pty_init(void *frontend, void **backend_handle, Conf *conf,
 #endif
 
 #ifndef NOT_X_WINDOWS		       /* for Mac OS X native compilation */
-    windowid = get_windowid(pty->frontend);
+    got_windowid = get_windowid(pty->frontend, &windowid);
 #endif
 
     /*
@@ -909,7 +910,7 @@ static const char *pty_init(void *frontend, void **backend_handle, Conf *conf,
 	     */
 	}
 #ifndef NOT_X_WINDOWS		       /* for Mac OS X native compilation */
-	{
+	if (got_windowid) {
 	    char *windowid_env_var = dupprintf("WINDOWID=%ld", windowid);
 	    putenv(windowid_env_var);
 	    /* We mustn't free windowid_env_var, as putenv links it into the
diff --git a/unix/x11misc.h b/unix/x11misc.h
index 0ad14764..159d4226 100644
--- a/unix/x11misc.h
+++ b/unix/x11misc.h
@@ -12,4 +12,9 @@
  */
 void x11_ignore_error(Display *disp, unsigned char errcode);
 
+/*
+ * gtkmisc.c
+ */
+Display *get_x11_display(void);
+
 #endif