diff --git a/base/file_utils.cc b/base/file_utils.cc
index 8253660..e6095f7 100644
--- a/base/file_utils.cc
+++ b/base/file_utils.cc
@@ -159,6 +159,7 @@ file_utils::zero_superblock(std::string const &path)
 		free(buffer);
 		throw runtime_error("couldn't zero superblock");
 	}
+	free(buffer);
 }
 
 //----------------------------------------------------------------