diff --git a/library/md5.c b/library/md5.c
index 88d50c6..87e2b1d 100644
--- a/library/md5.c
+++ b/library/md5.c
@@ -218,7 +218,7 @@
     size_t fill;
     uint32_t left;
 
-    if( ilen <= 0 )
+    if( ilen == 0 )
         return;
 
     left = ctx->total[0] & 0x3F;