diff --git a/src/go/mongolib/proto/replstatus.go b/src/go/mongolib/proto/replstatus.go
index 2c123321..72e9f0cb 100644
--- a/src/go/mongolib/proto/replstatus.go
+++ b/src/go/mongolib/proto/replstatus.go
@@ -75,8 +75,8 @@ type RSConfig struct {
 }
 
 type LastErrorDefaults struct {
-	W        int32 `bson:"w"`
-	WTimeout int32 `bson:"wtimeout"`
+	W        interface{} `bson:"w"`
+	WTimeout int32       `bson:"wtimeout"`
 }
 
 type RSSettings struct {