diff --git a/Modules/md5.c b/Modules/md5.c
index f6d0e37..642f0bd 100644
--- a/Modules/md5.c
+++ b/Modules/md5.c
@@ -325,7 +325,7 @@
 {
     const md5_byte_t *p = data;
     unsigned int left = nbytes;
-    int offset = (pms->count[0] >> 3) & 63;
+    unsigned int offset = (pms->count[0] >> 3) & 63;
     md5_word_t nbits = (md5_word_t)(nbytes << 3);
 
     if (nbytes <= 0)