diff --git a/config.c b/config.c
index 098da3066c..7f6e27ac8a 100644
--- a/config.c
+++ b/config.c
@@ -2135,6 +2135,9 @@ int git_config_set_multivar_in_file(const char *config_filename,
 					  contents_sz - copy_begin) <
 			    contents_sz - copy_begin)
 				goto write_err_out;
+
+		munmap(contents, contents_sz);
+		contents = NULL;
 	}
 
 	if (commit_lock_file(lock) < 0) {