diff --git a/gremlin-python/src/main/python/gremlin_python/structure/io/graphbinaryV1.py b/gremlin-python/src/main/python/gremlin_python/structure/io/graphbinaryV1.py
index 39a0c3a678a..14c73e48a38 100644
--- a/gremlin-python/src/main/python/gremlin_python/structure/io/graphbinaryV1.py
+++ b/gremlin-python/src/main/python/gremlin_python/structure/io/graphbinaryV1.py
@@ -118,6 +118,9 @@ class DataType(Enum):
 
 NULL_BYTES = [DataType.null.value, 0x01]
 
+# null type code as a plain int, so the per-read null check skips the aenum lookup
+_NULL = DataType.null.value
+
 
 def _make_packer(format_string):
     packer = struct.Struct(format_string)
@@ -187,6 +190,9 @@ def __init__(self, deserializer_map=None):
         self.deserializers = _deserializers.copy()
         if deserializer_map:
             self.deserializers.update(deserializer_map)
+        # Mirror of self.deserializers keyed by int type code instead of DataType.
+        # Avoids the per-read DataType(bt) call, whose aenum construction negatively affects performance on large results.
+        self._deserializer_by_type_code = {dt.value: des.objectify for dt, des in self.deserializers.items()}
 
     def read_object(self, b):
         if isinstance(b, bytearray):
@@ -197,11 +203,15 @@ def read_object(self, b):
     def to_object(self, buff, data_type=None, nullable=True):
         if data_type is None:
             bt = uint8_unpack(buff.read(1))
-            if bt == DataType.null.value:
+            if bt == _NULL:
                 if nullable:
                     buff.read(1)
                 return None
-            return self.deserializers[DataType(bt)].objectify(buff, self, nullable)
+            try:
+                objectify = self._deserializer_by_type_code[bt]
+            except KeyError:
+                raise ValueError("%r is not a valid DataType" % bt) from None
+            return objectify(buff, self, nullable)
         else:
             return self.deserializers[data_type].objectify(buff, self, nullable)