diff --git a/src/network/bmproto.py b/src/network/bmproto.py
index aff6cd0c..1f1c67bd 100644
--- a/src/network/bmproto.py
+++ b/src/network/bmproto.py
@@ -300,7 +300,7 @@ class BMProto(AdvancedDispatcher, ObjectTracker):
     def _command_inv(self, dandelion=False):
         items = self.decode_payload_content("l32s")
 
-        if len(items) >= BMProto.maxObjectCount:
+        if len(items) > BMProto.maxObjectCount:
             logger.error("Too many items in %sinv message!", "d" if dandelion else "")
             raise BMProtoExcessiveDataError()
         else:
diff --git a/src/network/tcp.py b/src/network/tcp.py
index 163cbd85..6cba566f 100644
--- a/src/network/tcp.py
+++ b/src/network/tcp.py
@@ -180,7 +180,11 @@ class TCPConnection(BMProto, TLSDispatcher):
         for hash, storedValue in bigInvList.items():
             payload += hash
             objectCount += 1
-            if objectCount >= BMProto.maxObjectCount:
+
+            # Remove -1 below when sufficient time has passed for users to
+            # upgrade to versions of PyBitmessage that accept inv with 50,000
+            # items
+            if objectCount >= BMProto.maxObjectCount - 1:
                 sendChunk()
                 payload = b''
                 objectCount = 0