diff --git a/gerbv/src/callbacks.h b/gerbv/src/callbacks.h

index c021e1b..9b9af3c 100644

--- a/gerbv/src/callbacks.h

+++ b/gerbv/src/callbacks.h

@@ -26,7 +26,7 @@

     \ingroup gerbv

 */

-enum {

+static enum {

 	CALLBACKS_SAVE_PROJECT_AS,

 	CALLBACKS_SAVE_FILE_PS,

 	CALLBACKS_SAVE_FILE_PDF,

@@ -43,7 +43,7 @@ enum {

 } CALLBACKS_SAVE_FILE_TYPE;

-enum {

+static enum {

 	LAYER_SELECTED =	-1,

 	LAYER_ALL_ON =		-2,

 	LAYER_ALL_OFF =		-3,