diff --git a/object-file.c b/object-file.c
index bd84ee4ca36811..0071655b698063 100644
--- a/object-file.c
+++ b/object-file.c
@@ -1785,7 +1785,7 @@ void *read_object_with_reference(struct repository *r,
 }
 
 static void hash_object_body(const struct git_hash_algo *algo, git_hash_ctx *c,
-			     const void *buf, unsigned long len,
+			     const void *buf, size_t len,
 			     struct object_id *oid,
 			     char *hdr, size_t *hdrlen)
 {
@@ -1805,7 +1805,7 @@ static void write_object_file_prepare(const struct git_hash_algo *algo,
 	/* Generate the header */
 	*hdrlen = format_object_header(hdr, *hdrlen, type, len);
 
-	/* Sha1.. */
+	/* Hash (function pointers) computation */
 	hash_object_body(algo, &c, buf, len, oid, hdr, hdrlen);
 }
 
diff --git a/sha1dc_git.c b/sha1dc_git.c
index 5c300e812e0a11..65a6f1f2cd1bc2 100644
--- a/sha1dc_git.c
+++ b/sha1dc_git.c
@@ -25,10 +25,9 @@ void git_SHA1DCFinal(unsigned char hash[20], SHA1_CTX *ctx)
 /*
  * Same as SHA1DCUpdate, but adjust types to match git's usual interface.
  */
-void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *vdata, unsigned long len)
+void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *vdata, size_t len)
 {
 	const char *data = vdata;
-	/* We expect an unsigned long, but sha1dc only takes an int */
 	while (len > INT_MAX) {
 		SHA1DCUpdate(ctx, data, INT_MAX);
 		data += INT_MAX;
diff --git a/sha1dc_git.h b/sha1dc_git.h
index 41e1c3fd3f787e..847b38fb4b9f23 100644
--- a/sha1dc_git.h
+++ b/sha1dc_git.h
@@ -15,7 +15,7 @@ void git_SHA1DCInit(SHA1_CTX *);
 #endif
 
 void git_SHA1DCFinal(unsigned char [20], SHA1_CTX *);
-void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *data, unsigned long len);
+void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *data, size_t len);
 
 #define platform_SHA_CTX SHA1_CTX
 #define platform_SHA1_Init git_SHA1DCInit
diff --git a/t/t1007-hash-object.sh b/t/t1007-hash-object.sh
index 428298fa2934d6..b30fb1282aa054 100755
--- a/t/t1007-hash-object.sh
+++ b/t/t1007-hash-object.sh
@@ -252,7 +252,7 @@ test_expect_success '--literally with extra-long type' '
 	echo example | git hash-object -t $t --literally --stdin
 '
 
-test_expect_failure EXPENSIVE,SIZE_T_IS_64BIT,!LONG_IS_64BIT \
+test_expect_success EXPENSIVE,SIZE_T_IS_64BIT,!LONG_IS_64BIT \
 		'files over 4GB hash literally' '
 	test-tool genzeros $((5*1024*1024*1024)) >big &&
 	test_oid large5GB >expect &&