diff --git a/tools/firmware-utils/src/mkzynfw.c b/tools/firmware-utils/src/mkzynfw.c
index 130d95a8c..bc512c82e 100755
--- a/tools/firmware-utils/src/mkzynfw.c
+++ b/tools/firmware-utils/src/mkzynfw.c
@@ -794,7 +794,7 @@ parse_opt_block(char ch, char *arg)
 	struct fw_block *block;
 	int i;
 
-	if ( num_blocks > MAX_NUM_BLOCKS ) {
+	if ( num_blocks >= MAX_NUM_BLOCKS ) {
 		ERR("too many blocks specified");
 		return -1;
 	}