diff --git a/src/gallium/auxiliary/driver_ddebug/dd_draw.c b/src/gallium/auxiliary/driver_ddebug/dd_draw.c
index f9d9ed54b3e..1d8e57767ed 100644
--- a/src/gallium/auxiliary/driver_ddebug/dd_draw.c
+++ b/src/gallium/auxiliary/driver_ddebug/dd_draw.c
@@ -57,7 +57,7 @@ dd_get_debug_filename_and_mkdir(char *buf, size_t buflen, bool verbose)
       fprintf(stderr, "dd: can't create a directory (%i)\n", errno);
 
    snprintf(buf, buflen, "%s/%s_%u_%08u", dir, proc_name, getpid(),
-            p_atomic_inc_return(&index) - 1);
+            (unsigned int)p_atomic_inc_return(&index) - 1);
 
    if (verbose)
       fprintf(stderr, "dd: dumping to file %s\n", buf);