diff --git a/entry.c b/entry.c
index 9b0f968a70..1c9df62b30 100644
--- a/entry.c
+++ b/entry.c
@@ -82,11 +82,13 @@ static int create_file(const char *path, unsigned int mode)
 	return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
 }
 
-void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
+void *read_blob_entry(const struct cache_entry *ce, size_t *size)
 {
 	enum object_type type;
-	void *blob_data = read_object_file(&ce->oid, &type, size);
+	unsigned long ul;
+	void *blob_data = read_object_file(&ce->oid, &type, &ul);
 
+	*size = ul;
 	if (blob_data) {
 		if (type == OBJ_BLOB)
 			return blob_data;
@@ -271,7 +273,7 @@ static int write_entry(struct cache_entry *ce, char *path, struct conv_attrs *ca
 	int fd, ret, fstat_done = 0;
 	char *new_blob;
 	struct strbuf buf = STRBUF_INIT;
-	unsigned long size;
+	size_t size;
 	ssize_t wrote;
 	size_t newsize = 0;
 	struct stat st;
diff --git a/entry.h b/entry.h
index 2254c62727..252fd24c2e 100644
--- a/entry.h
+++ b/entry.h
@@ -52,7 +52,7 @@ int finish_delayed_checkout(struct checkout *state, int *nr_checkouts,
  */
 void unlink_entry(const struct cache_entry *ce);
 
-void *read_blob_entry(const struct cache_entry *ce, unsigned long *size);
+void *read_blob_entry(const struct cache_entry *ce, size_t *size);
 int fstat_checkout_output(int fd, const struct checkout *state, struct stat *st);
 void update_ce_after_write(const struct checkout *state, struct cache_entry *ce,
 			   struct stat *st);
diff --git a/parallel-checkout.c b/parallel-checkout.c
index ed9c999520..8dd7e7bad4 100644
--- a/parallel-checkout.c
+++ b/parallel-checkout.c
@@ -261,7 +261,7 @@ static int write_pc_item_to_fd(struct parallel_checkout_item *pc_item, int fd,
 	struct stream_filter *filter;
 	struct strbuf buf = STRBUF_INIT;
 	char *blob;
-	unsigned long size;
+	size_t size;
 	ssize_t wrote;
 
 	/* Sanity check */
diff --git a/t/t1051-large-conversion.sh b/t/t1051-large-conversion.sh
index bff86c1320..8b23d86260 100755
--- a/t/t1051-large-conversion.sh
+++ b/t/t1051-large-conversion.sh
@@ -85,7 +85,7 @@ test_expect_success 'ident converts on output' '
 
 # This smudge filter prepends 5GB of zeros to the file it checks out. This
 # ensures that smudging doesn't mangle large files on 64-bit Windows.
-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 convert on output' '
 	test_commit test small "a small file" &&
 	test_config filter.makelarge.smudge \