diff --git a/cache.h b/cache.h
index 1dba405703..f8329aedfd 100644
--- a/cache.h
+++ b/cache.h
@@ -96,8 +96,8 @@ static inline unsigned int create_ce_mode(unsigned int mode)
 
 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 
-struct cache_entry **active_cache;
-unsigned int active_nr, active_alloc, active_cache_changed;
+extern struct cache_entry **active_cache;
+extern unsigned int active_nr, active_alloc, active_cache_changed;
 
 #define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY"
 #define DEFAULT_DB_ENVIRONMENT ".git/objects"
diff --git a/object.h b/object.h
index d53a35a4d7..09700d3760 100644
--- a/object.h
+++ b/object.h
@@ -15,8 +15,8 @@ struct object {
 	struct object_list *refs;
 };
 
-int nr_objs;
-struct object **objs;
+extern int nr_objs;
+extern struct object **objs;
 
 struct object *lookup_object(unsigned char *sha1);