diff --git a/cmake/cmake.h.in b/cmake/cmake.h.in
index 3882148b..f8fcbc58 100644
--- a/cmake/cmake.h.in
+++ b/cmake/cmake.h.in
@@ -48,6 +48,7 @@
 #cmakedefine01 HAVE_BINARY_SETPGRP
 #cmakedefine01 HAVE_PANGO_FONT_FAMILY_IS_MONOSPACE
 #cmakedefine01 HAVE_PANGO_FONT_MAP_LIST_FAMILIES
+#cmakedefine01 HAVE_G_APPLICATION_DEFAULT_FLAGS
 
 #cmakedefine01 HAVE_AES_NI
 #cmakedefine01 HAVE_SHA_NI
diff --git a/cmake/gtk.cmake b/cmake/gtk.cmake
index 13ff7705..9c70c685 100644
--- a/cmake/gtk.cmake
+++ b/cmake/gtk.cmake
@@ -84,6 +84,10 @@ if(GTK_FOUND)
       ${HAVE_PANGO_FONT_FAMILY_IS_MONOSPACE} PARENT_SCOPE)
     set(HAVE_PANGO_FONT_MAP_LIST_FAMILIES
       ${HAVE_PANGO_FONT_MAP_LIST_FAMILIES} PARENT_SCOPE)
+    check_c_source_compiles("
+      #include <gtk/gtk.h>
+      int f = G_APPLICATION_DEFAULT_FLAGS;
+      int main(void) {}" HAVE_G_APPLICATION_DEFAULT_FLAGS)
   endfunction()
   pango_check_subscope()
 endif()
diff --git a/unix/gtkcompat.h b/unix/gtkcompat.h
index 6ab5c809..2e8e8b88 100644
--- a/unix/gtkcompat.h
+++ b/unix/gtkcompat.h
@@ -218,3 +218,7 @@
     gdk_cursor_new_for_display(gdk_display_get_default(), cur)
 
 #endif /* 3.0 */
+
+#if !HAVE_G_APPLICATION_DEFAULT_FLAGS
+#define G_APPLICATION_DEFAULT_FLAGS G_APPLICATION_FLAGS_NONE
+#endif
diff --git a/unix/main-gtk-application.c b/unix/main-gtk-application.c
index 2bc1371a..3aaf6af7 100644
--- a/unix/main-gtk-application.c
+++ b/unix/main-gtk-application.c
@@ -79,6 +79,7 @@ https://wiki.gnome.org/Projects/GTK%2B/OSX/Bundling has some links.
 
 #include "putty.h"
 #include "gtkmisc.h"
+#include "gtkcompat.h"
 
 char *x_get_default(const char *key) { return NULL; }