diff --git a/gui/canvas.h b/gui/canvas.h
index 300a63d4..1a0d024f 100644
--- a/gui/canvas.h
+++ b/gui/canvas.h
@@ -33,8 +33,6 @@ typedef struct canvas_tag { int unused; } * canvas_handle;
 typedef struct canvas_module_tag { int unused; } * canvas_module_handle;
 typedef struct canvas_port_tag { int unused; } * canvas_port_handle;
 
-enum ModuleType { Input, Output, InputOutput };
-
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/gui/common.h b/gui/common.h
index 120fb5da..9a2340cb 100644
--- a/gui/common.h
+++ b/gui/common.h
@@ -41,4 +41,6 @@
 
 #include "canvas.h"
 
+enum ModuleType { Input, Output, InputOutput };
+
 #endif /* #ifndef COMMON_H__15E63B7A_8350_4ABD_B04C_592158354949__INCLUDED */