diff --git a/src/libgit2/commit.c b/src/libgit2/commit.c
index 10df43623..633279227 100644
--- a/src/libgit2/commit.c
+++ b/src/libgit2/commit.c
@@ -340,7 +340,7 @@ int git_commit_amend(
 {
 	git_repository *repo;
 	git_oid tree_id;
-	git_reference *ref;
+	git_reference *ref = NULL;
 	int error;
 
 	GIT_ASSERT_ARG(id);
diff --git a/src/libgit2/fetchhead.c b/src/libgit2/fetchhead.c
index 08be282a5..1555d1cd9 100644
--- a/src/libgit2/fetchhead.c
+++ b/src/libgit2/fetchhead.c
@@ -106,7 +106,7 @@ static int fetchhead_ref_write(
 	git_fetchhead_ref *fetchhead_ref)
 {
 	char oid[GIT_OID_MAX_HEXSIZE + 1];
-	const char *type, *name;
+	const char *type = NULL, *name = NULL;
 	int head = 0;
 
 	GIT_ASSERT_ARG(file);
diff --git a/src/libgit2/index.c b/src/libgit2/index.c
index 2f1f1b8d5..e8a692169 100644
--- a/src/libgit2/index.c
+++ b/src/libgit2/index.c
@@ -2510,7 +2510,7 @@ static int read_entry(
 {
 	size_t path_length, path_offset, entry_size;
 	const char *path_ptr;
-	struct entry_common *source_common;
+	struct entry_common *source_common = NULL;
 	index_entry_short_sha1 source_sha1;
 #ifdef GIT_EXPERIMENTAL_SHA256
 	index_entry_short_sha256 source_sha256;
@@ -2862,7 +2862,7 @@ static int write_disk_entry(
 	const char *last)
 {
 	void *mem = NULL;
-	struct entry_common *ondisk_common;
+	struct entry_common *ondisk_common = NULL;
 	size_t path_len, path_offset, disk_size;
 	int varint_len = 0;
 	char *path;
@@ -2951,7 +2951,7 @@ static int write_disk_entry(
 	path_offset = index_entry_path_offset(index->oid_type, entry->flags);
 
 	if (entry->flags & GIT_INDEX_ENTRY_EXTENDED) {
-		struct entry_common *ondisk_ext;
+		struct entry_common *ondisk_ext = NULL;
 		uint16_t flags_extended = htons(entry->flags_extended &
 			GIT_INDEX_ENTRY_EXTENDED_FLAGS);
 
diff --git a/src/libgit2/merge.c b/src/libgit2/merge.c
index eabb4bfa3..b73454d77 100644
--- a/src/libgit2/merge.c
+++ b/src/libgit2/merge.c
@@ -936,7 +936,7 @@ static int merge_conflict_resolve_contents(
 	git_merge_file_result result = {0};
 	git_merge_driver *driver;
 	git_merge_driver__builtin builtin = {{0}};
-	git_index_entry *merge_result;
+	git_index_entry *merge_result = NULL;
 	git_odb *odb = NULL;
 	const char *name;
 	bool fallback = false;
diff --git a/src/libgit2/repository.c b/src/libgit2/repository.c
index a88217e65..e648e8e1a 100644
--- a/src/libgit2/repository.c
+++ b/src/libgit2/repository.c
@@ -669,7 +669,7 @@ static int validate_ownership_path(bool *is_safe, const char *path)
 
 static int validate_ownership(git_repository *repo)
 {
-	const char *validation_paths[3] = { NULL }, *path;
+	const char *validation_paths[3] = { NULL }, *path = NULL;
 	size_t validation_len = 0, i;
 	bool is_safe = false;
 	int error = 0;
@@ -1412,7 +1412,7 @@ int git_repository_config__weakptr(git_config **out, git_repository *repo)
 		git_str xdg_buf = GIT_STR_INIT;
 		git_str programdata_buf = GIT_STR_INIT;
 		bool use_env = repo->use_env;
-		git_config *config;
+		git_config *config = NULL;
 
 		if (!(error = config_path_system(&system_buf, use_env)) &&
 		    !(error = config_path_global(&global_buf, use_env))) {
diff --git a/src/libgit2/transports/httpclient.c b/src/libgit2/transports/httpclient.c
index e25e0a73a..e27d40b5f 100644
--- a/src/libgit2/transports/httpclient.c
+++ b/src/libgit2/transports/httpclient.c
@@ -553,7 +553,7 @@ static int apply_credentials(
 {
 	git_http_auth_context *auth = server->auth_context;
 	git_vector *challenges = &server->auth_challenges;
-	const char *challenge;
+	const char *challenge = NULL;
 	git_str token = GIT_STR_INIT;
 	int error = 0;
 
diff --git a/src/util/net.c b/src/util/net.c
index d7ca48a59..136a97a7a 100644
--- a/src/util/net.c
+++ b/src/util/net.c
@@ -185,7 +185,7 @@ static int url_parse_authority(
 	size_t len)
 {
 	const char *c, *hostport_end, *host_end = NULL,
-	           *userpass_end, *user_end = NULL;
+	           *userpass_end = NULL, *user_end = NULL;
 
 	enum {
 		HOSTPORT, HOST, IPV6, HOST_END, USERPASS, USER
@@ -574,7 +574,7 @@ int git_net_url_parse_http(
 	const char *given)
 {
 	git_net_url_parser parser = GIT_NET_URL_PARSER_INIT;
-	const char *c, *authority, *path = NULL;
+	const char *c, *authority = NULL, *path = NULL;
 	size_t authority_len = 0, path_len = 0;
 	int error;
 
@@ -661,7 +661,7 @@ static bool has_at(const char *str)
 int git_net_url_parse_scp(git_net_url *url, const char *given)
 {
 	const char *default_port = default_port_for_scheme("ssh");
-	const char *c, *user, *host, *port = NULL, *path = NULL;
+	const char *c, *user = NULL, *host = NULL, *port = NULL, *path = NULL;
 	size_t user_len = 0, host_len = 0, port_len = 0;
 	unsigned short bracket = 0;