diff --git a/src/kits/app/r5_message.cpp b/src/kits/app/r5_message.cpp
index 46ced99264..53fd8e7aef 100644
--- a/src/kits/app/r5_message.cpp
+++ b/src/kits/app/r5_message.cpp
@@ -284,6 +284,8 @@ unflatten_r5_message(uint32 format, BMessage *message, const char *flatBuffer)
 status_t
 unflatten_r5_message(uint32 format, BMessage *message, BDataIO *stream)
 {
+	message->MakeEmpty();
+
 	TReadHelper reader(stream);
 	BMessage::Private messagePrivate(message);
 	BMessage::message_header *header = messagePrivate.GetMessageHeader();
@@ -360,6 +362,9 @@ unflatten_r5_message(uint32 format, BMessage *message, BDataIO *stream)
 		} else
 			reader(dataSize);
 
+		if (dataSize <= 0)
+			return B_ERROR;
+
 		// name
 		uint8 nameLength;
 		reader(nameLength);