diff --git a/dlls/gphoto2.ds/gphoto2_main.c b/dlls/gphoto2.ds/gphoto2_main.c
index fcd4b168c93..83e2eea7c2e 100644
--- a/dlls/gphoto2.ds/gphoto2_main.c
+++ b/dlls/gphoto2.ds/gphoto2_main.c
@@ -61,7 +61,7 @@ static TW_UINT16 GPHOTO2_GetIdentity( pTW_IDENTITY, pTW_IDENTITY);
 static TW_UINT16 GPHOTO2_OpenDS( pTW_IDENTITY, pTW_IDENTITY);
 #endif
 
-TW_UINT16 GPHOTO2_SourceControlHandler (
+static TW_UINT16 GPHOTO2_SourceControlHandler (
    pTW_IDENTITY pOrigin,
    TW_UINT16    DAT,
    TW_UINT16    MSG,