@@ -54,8 +54,15 @@
 	[f close];
 
 	TEST(@"-[digest]",
 	    !memcmp([md5 digest], testfile_md5, OF_MD5_DIGEST_SIZE) &&
 	    !memcmp([sha1 digest], testfile_sha1, OF_MD5_DIGEST_SIZE))
+
+	EXPECT_EXCEPTION(@"Detect invalid call of -[updateWithBuffer] #1",
+	    OFHashAlreadyCalculatedException, [md5 updateWithBuffer: ""
+							     ofSize: 1])
+	EXPECT_EXCEPTION(@"Detect invalid call of -[updateWithBuffer] #2",
+	    OFHashAlreadyCalculatedException, [sha1 updateWithBuffer: ""
+							      ofSize: 1])
 
 	[pool release];
 }