diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index b13561cf73b11b..128c901fa8e82d 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -104,7 +104,7 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 	struct object_id oid;
 	enum object_type type;
 	char *buf;
-	unsigned long size;
+	unsigned long size = 0;
 	struct object_context obj_context = {0};
 	struct object_info oi = OBJECT_INFO_INIT;
 	struct strbuf sb = STRBUF_INIT;
diff --git a/fsck.c b/fsck.c
index 9fc4c25ffd59ba..ad04b24ff13a5a 100644
--- a/fsck.c
+++ b/fsck.c
@@ -925,7 +925,7 @@ static int fsck_commit(const struct object_id *oid,
 {
 	struct object_id tree_oid, parent_oid;
 	unsigned author_count;
-	int err;
+	int err = 0;
 	const char *buffer_begin = buffer;
 	const char *buffer_end = buffer + size;
 	const char *p;
diff --git a/pack-mtimes.c b/pack-mtimes.c
index cdf30b8d2b0e80..c1f531d45a0ad6 100644
--- a/pack-mtimes.c
+++ b/pack-mtimes.c
@@ -29,7 +29,7 @@ static int load_pack_mtimes_file(char *mtimes_file,
 	int fd, ret = 0;
 	struct stat st;
 	uint32_t *data = NULL;
-	size_t mtimes_size, expected_size;
+	size_t mtimes_size = 0, expected_size;
 	struct mtimes_header header;
 
 	fd = git_open(mtimes_file);
diff --git a/pack-revindex.c b/pack-revindex.c
index d3832478d99edf..3b007d771b362e 100644
--- a/pack-revindex.c
+++ b/pack-revindex.c
@@ -208,7 +208,7 @@ static int load_revindex_from_disk(char *revindex_name,
 	int fd, ret = 0;
 	struct stat st;
 	void *data = NULL;
-	size_t revindex_size;
+	size_t revindex_size = 0;
 	struct revindex_header *hdr;
 
 	if (git_env_bool(GIT_TEST_REV_INDEX_DIE_ON_DISK, 0))