diff --git a/cmake/gtk.cmake b/cmake/gtk.cmake
index 145f214b..85ecb7de 100644
--- a/cmake/gtk.cmake
+++ b/cmake/gtk.cmake
@@ -12,6 +12,9 @@ macro(try_pkg_config_gtk VER PACKAGENAME)
       (PUTTY_GTK_VERSION STREQUAL ANY OR PUTTY_GTK_VERSION STREQUAL ${VER}))
     find_package(PkgConfig)
     pkg_check_modules(GTK ${PACKAGENAME})
+    if(GTK_FOUND)
+      set(GTK_VERSION ${VER})
+    endif()
   endif()
 endmacro()
 try_pkg_config_gtk(3 gtk+-3.0)
diff --git a/unix/CMakeLists.txt b/unix/CMakeLists.txt
index 0490cf5c..9bdd2522 100644
--- a/unix/CMakeLists.txt
+++ b/unix/CMakeLists.txt
@@ -155,17 +155,19 @@ if(GTK_FOUND)
     ${GTK_LIBRARIES} ${X11_LIBRARIES})
   installed_program(pterm)
 
-  add_executable(ptermapp
-    pterm.c
-    main-gtk-application.c
-    ${CMAKE_SOURCE_DIR}/stubs/nocmdline.c
-    ${CMAKE_SOURCE_DIR}/stubs/nogss.c
-    ${CMAKE_SOURCE_DIR}/proxy/nosshproxy.c
-    pty.c)
-  be_list(ptermapp pterm)
-  target_link_libraries(ptermapp
-    guiterminal eventloop settings charset utils
-    ${GTK_LIBRARIES} ${X11_LIBRARIES})
+  if(GTK_VERSION GREATER_EQUAL 3)
+    add_executable(ptermapp
+      pterm.c
+      main-gtk-application.c
+      ${CMAKE_SOURCE_DIR}/stubs/nocmdline.c
+      ${CMAKE_SOURCE_DIR}/stubs/nogss.c
+      ${CMAKE_SOURCE_DIR}/proxy/nosshproxy.c
+      pty.c)
+    be_list(ptermapp pterm)
+    target_link_libraries(ptermapp
+      guiterminal eventloop settings charset utils
+      ${GTK_LIBRARIES} ${X11_LIBRARIES})
+  endif()
 
   add_executable(putty
     putty.c
@@ -179,15 +181,17 @@ if(GTK_FOUND)
     PROPERTIES LINK_INTERFACE_MULTIPLICITY 2)
   installed_program(putty)
 
-  add_executable(puttyapp
-    putty.c
-    main-gtk-application.c
-    ${CMAKE_SOURCE_DIR}/stubs/nocmdline.c)
-  be_list(puttyapp PuTTY SSH SERIAL OTHERBACKENDS)
-  target_link_libraries(puttyapp
-    guiterminal eventloop sshclient otherbackends settings
-    network crypto charset utils
-    ${GTK_LIBRARIES} ${X11_LIBRARIES})
+  if(GTK_VERSION GREATER_EQUAL 3)
+    add_executable(puttyapp
+      putty.c
+      main-gtk-application.c
+      ${CMAKE_SOURCE_DIR}/stubs/nocmdline.c)
+    be_list(puttyapp PuTTY SSH SERIAL OTHERBACKENDS)
+    target_link_libraries(puttyapp
+      guiterminal eventloop sshclient otherbackends settings
+      network crypto charset utils
+      ${GTK_LIBRARIES} ${X11_LIBRARIES})
+  endif()
 
   add_executable(puttytel
     putty.c
diff --git a/unix/main-gtk-application.c b/unix/main-gtk-application.c
index fb924009..b6c2807b 100644
--- a/unix/main-gtk-application.c
+++ b/unix/main-gtk-application.c
@@ -84,21 +84,8 @@ char *x_get_default(const char *key) { return NULL; }
 const bool buildinfo_gtk_relevant = true;
 
 #if !GTK_CHECK_VERSION(3,0,0)
-/* This front end only works in GTK 3. If that's not what we've got,
- * it's easier to just turn this program into a trivial stub by ifdef
- * in the source than it is to remove it in the makefile edifice. */
-int main(int argc, char **argv)
-{
-    fprintf(stderr, "GtkApplication frontend doesn't work pre-GTK3\n");
-    return 1;
-}
-GtkWidget *make_gtk_toplevel_window(GtkFrontend *frontend) { return NULL; }
-void launch_duplicate_session(Conf *conf) {}
-void launch_new_session(void) {}
-void launch_saved_session(const char *str) {}
-void session_window_closed(void) {}
-void window_setup_error(const char *errmsg) {}
-#else /* GTK_CHECK_VERSION(3,0,0) */
+#error This front end only works in GTK 3
+#endif
 
 static void startup(GApplication *app, gpointer user_data)
 {
@@ -336,5 +323,3 @@ int main(int argc, char **argv)
 
     return status;
 }
-
-#endif /* GTK_CHECK_VERSION(3,0,0) */