diff --git a/src/google/protobuf/text_format.h b/src/google/protobuf/text_format.h
index 25ef58b3408d..7360aa29e00e 100644
--- a/src/google/protobuf/text_format.h
+++ b/src/google/protobuf/text_format.h
@@ -440,6 +440,7 @@ class PROTOBUF_EXPORT TextFormat {
     // particular Descriptor.
     // Returns "true" if the registration succeeded, or "false" if there is
     // already a printer for that Descriptor.
+    // Takes ownership of the printer on successful registration.
     bool RegisterMessagePrinter(const Descriptor* descriptor,
                                 const MessagePrinter* printer);