diff --git a/src/pack.c b/src/pack.c
index 7c1cfe03e..516e0f3ca 100644
--- a/src/pack.c
+++ b/src/pack.c
@@ -620,7 +620,7 @@ int git_packfile_unpack(
 	struct pack_chain_elem *elem = NULL, *stack;
 	git_pack_cache_entry *cached = NULL;
 	struct pack_chain_elem small_stack[SMALL_STACK_SIZE];
-	size_t stack_size, elem_pos;
+	size_t stack_size = 0, elem_pos;
 	git_otype base_type;
 
 	/*