diff --git a/cli-app/cper-convert.c b/cli-app/cper-convert.c
index d1caeb6..84ce618 100644
--- a/cli-app/cper-convert.c
+++ b/cli-app/cper-convert.c
@@ -103,7 +103,7 @@
 	char *fbuff = malloc(fsize);
 	size_t readsize = fread(fbuff, 1, (long)fsize, cper_file);
 	if (readsize != (size_t)fsize) {
-		printf("Could not read CPER file '%s', read returned %ld bytes.\n",
+		printf("Could not read CPER file '%s', read returned %zu bytes.\n",
 		       in_file, readsize);
 		return;
 	}