diff --git a/buffer.c b/buffer.c
index e9bdbb7..c11b67f 100644
--- a/buffer.c
+++ b/buffer.c
@@ -338,12 +338,13 @@ buffer_clear(buffer_t *self) {
 
 void
 buffer_print(buffer_t *self) {
+  int i;
   size_t len = self->len;
 
   printf("\n ");
 
   // hex
-  for (int i = 0; i < len; ++i) {
+  for (i = 0; i < len; ++i) {
     printf(" %02x", self->alloc[i]);
     if ((i + 1) % 8 == 0) printf("\n ");
   }