diff --git a/proto/mf.proto b/proto/mf.proto
index 12ca402..ba9ab5e 100644
--- a/proto/mf.proto
+++ b/proto/mf.proto
@@ -31,7 +31,6 @@ message MFFile {
 }
 
 message MFFilePath {
-
     // required attributes:
     string path = 101;
     uint64 size = 102;
@@ -41,9 +40,9 @@ message MFFilePath {
 
     // optional per-file metadata
     optional string mimeType = 301;
-    optional string mtime = 302;
-    optional string ctime = 303;
-    optional string atime = 304;
+    optional google.protobuf.Timestamp mtime = 302;
+    optional google.protobuf.Timestamp ctime = 303;
+    optional google.protobuf.Timestamp atime = 304;
 
 }