diff --git a/src/x49gpng/main.c b/src/x49gpng/main.c
index 21c1df0..6e6803d 100644
--- a/src/x49gpng/main.c
+++ b/src/x49gpng/main.c
@@ -129,7 +129,6 @@ uint32_t do_arm_semihosting( CPUState* env )
                     env->regs[ 1 ], env->regs[ 2 ], env->regs[ 3 ], env->regs[ 4 ], env->regs[ 5 ], env->regs[ 6 ], env->regs[ 7 ] );
 #endif
 
-#if 1
             switch ( env->regs[ 0 ] ) {
                 case 305: /* Beep */
                     printf( "%s: BEEP: frequency %u, time %u, override %u\n", __FUNCTION__, env->regs[ 1 ], env->regs[ 2 ],
@@ -150,7 +149,6 @@ uint32_t do_arm_semihosting( CPUState* env )
                 default:
                     break;
             }
-#endif
             break;
 
         default:
@@ -193,8 +191,13 @@ static void arm_sighnd( int sig )
 
 void x49gp_gtk_timer( void* data )
 {
+#if GTK_MAJOR_VERSION == 4
+    while ( g_main_context_pending( NULL ) )
+        g_main_context_iteration( NULL, false );
+#else
     while ( gtk_events_pending() )
         gtk_main_iteration_do( false );
+#endif
 
     x49gp_mod_timer( x49gp->gtk_timer, x49gp_get_clock() + X49GP_GTK_REFRESH_INTERVAL );
 }
@@ -230,7 +233,11 @@ int main( int argc, char** argv )
     char* progname = g_path_get_basename( argv[ 0 ] );
     char* progpath = g_path_get_dirname( argv[ 0 ] );
 
+#if GTK_MAJOR_VERSION == 4
+    gtk_init();
+#else
     gtk_init( &argc, &argv );
+#endif
 
     config_init( progname, argc, argv );