diff --git a/src/vo_postprocess/scale.c b/src/vo_postprocess/scale.c
index b7f1eed3f..a433751f5 100644
--- a/src/vo_postprocess/scale.c
+++ b/src/vo_postprocess/scale.c
@@ -114,7 +114,7 @@ static void * scale_init(const char *config) {
                 return NULL;
         }
 
-        const char *tmp = strdup(config);
+        char *tmp = strdup(config);
 
         s = (struct state_scale *) 
                         malloc(sizeof(struct state_scale));