diff --git a/include/git2/sys/merge.h b/include/git2/sys/merge.h
index bd0a8a4b7..ef4bc5aca 100644
--- a/include/git2/sys/merge.h
+++ b/include/git2/sys/merge.h
@@ -41,7 +41,7 @@ GIT_EXTERN(git_merge_driver *) git_merge_driver_lookup(const char *name);
 typedef struct git_merge_driver_source git_merge_driver_source;
 
 /** Get the repository that the source data is coming from. */
-GIT_EXTERN(const git_repository *) git_merge_driver_source_repo(
+GIT_EXTERN(git_repository *) git_merge_driver_source_repo(
 	const git_merge_driver_source *src);
 
 /** Gets the ancestor of the file to merge. */
diff --git a/src/merge_driver.c b/src/merge_driver.c
index a529aefda..666349b15 100644
--- a/src/merge_driver.c
+++ b/src/merge_driver.c
@@ -32,7 +32,7 @@ static struct merge_driver_registry merge_driver_registry;
 
 static void git_merge_driver_global_shutdown(void);
 
-const git_repository* git_merge_driver_source_repo(const git_merge_driver_source *src)
+git_repository* git_merge_driver_source_repo(const git_merge_driver_source *src)
 {
 	assert(src);
 	return src->repo;