diff --git a/sha-example.c b/sha-example.c
index 8f43496894e1e608601473ace85c8a07723d1982..8b3d505919e96eb5a97f19f2ee1252a481698e6f 100644
--- a/sha-example.c
+++ b/sha-example.c
@@ -11,7 +11,7 @@ display_hex(unsigned length, uint8_t *data)
   unsigned i;
 
   for (i = 0; i<length; i++)
-    printf("%2x ", data[i]);
+    printf("%02x ", data[i]);
 
   printf("\n");
 }