diff --git a/unix/gtkfont.c b/unix/gtkfont.c
index 1a9860ab..82c0dafa 100644
--- a/unix/gtkfont.c
+++ b/unix/gtkfont.c
@@ -3392,7 +3392,7 @@ void unifontsel_set_name(unifontsel *fontsel, const char *fontname)
      * Provide a default if given an empty or null font name.
      */
     if (!fontname || !*fontname)
-	fontname = "server:fixed";
+	fontname = DEFAULT_GTK_FONT;
 
     /*
      * Call the canonify_fontname function.
diff --git a/unix/gtkwin.c b/unix/gtkwin.c
index 69535c36..3c0ac10d 100644
--- a/unix/gtkwin.c
+++ b/unix/gtkwin.c
@@ -184,7 +184,7 @@ void connection_fatal(void *frontend, const char *p, ...)
 FontSpec *platform_default_fontspec(const char *name)
 {
     if (!strcmp(name, "Font"))
-	return fontspec_new("server:fixed");
+	return fontspec_new(DEFAULT_GTK_FONT);
     else
         return fontspec_new("");
 }
diff --git a/unix/unix.h b/unix/unix.h
index 90922451..36bf02bb 100644
--- a/unix/unix.h
+++ b/unix/unix.h
@@ -210,4 +210,13 @@ extern Backend serial_backend;
  */
 int so_peercred(int fd, int *pid, int *uid, int *gid);
 
+/*
+ * Default font setting, which can vary depending on NOT_X_WINDOWS.
+ */
+#ifdef NOT_X_WINDOWS
+#define DEFAULT_GTK_FONT "client:Monospace 12"
+#else
+#define DEFAULT_GTK_FONT "server:fixed"
+#endif
+
 #endif