diff --git a/libpostproc/postprocess.c b/libpostproc/postprocess.c
index af70bb3eeb0ccab5137ede1e160396881e18997a..acce0f273b07b1c8e6c2646e21b71e22d3745053 100644
--- a/libpostproc/postprocess.c
+++ b/libpostproc/postprocess.c
@@ -737,7 +737,7 @@ pp_mode *pp_get_mode_by_name_and_quality(const char *name, int quality)
         /* replace stuff from the replace Table */
         for(i=0; replaceTable[2*i]; i++){
             if(!strcmp(replaceTable[2*i], filterName)){
-                int newlen= strlen(replaceTable[2*i + 1]);
+                size_t newlen = strlen(replaceTable[2*i + 1]);
                 int plen;
                 int spaceLeft;