diff --git a/desmume/src/gtk/glx_3Demu.cpp b/desmume/src/gtk/glx_3Demu.cpp
index a0546b946..628fa6cd3 100644
--- a/desmume/src/gtk/glx_3Demu.cpp
+++ b/desmume/src/gtk/glx_3Demu.cpp
@@ -31,7 +31,7 @@ static bool glx_init(void) { return true; }
 static GLXContext ctx;
 static GLXPbuffer pbuf;
 
-void deinit_glx_3Demu(void)
+int deinit_glx_3Demu(void)
 {
     Display *dpy = glXGetCurrentDisplay();