diff --git a/contrib/tvmop/core/multiarray.py b/contrib/tvmop/core/multiarray.py
index ba72fe20d190..c8eed5b45368 100644
--- a/contrib/tvmop/core/multiarray.py
+++ b/contrib/tvmop/core/multiarray.py
@@ -32,7 +32,7 @@ def compute_dot(A, B):
     return C
 
 
-@defop(name="dot", target="cpu", dispatch=True, dtype=AllTypes)
+@defop(name="dot", target="cpu", dtype=AllTypes)
 def dot(dtype, fallback):
     cfg = autotvm.get_config()
     cfg.define_knob("bn", [64] if fallback else [64, 32])
diff --git a/contrib/tvmop/opdef.py b/contrib/tvmop/opdef.py
index 57537bac648e..1e0f34669b10 100644
--- a/contrib/tvmop/opdef.py
+++ b/contrib/tvmop/opdef.py
@@ -17,6 +17,7 @@
 
 # coding: utf-8
 import tvm
+import inspect
 from tvm import autotvm
 from itertools import product
 
@@ -48,7 +49,7 @@ class OpDef:
          without considering whether dimension size equals to one.
          TVM maps buffer[i][j][k] -> buffer[i][0][k] if dimension i's shape equals 1.
     """
-    def __init__(self, func, name, target, auto_broadcast, dispatch, **kwargs):
+    def __init__(self, func, name, target, auto_broadcast, **kwargs):
         # construct the value combination of the arguments
         # e.g., ldtype=["float32", "int32"], rdtype=["float16", "int16"]
         # arg_combination = [
@@ -69,7 +70,7 @@ def __init__(self, func, name, target, auto_broadcast, dispatch, **kwargs):
         self.name = name
         self.target = target
         self.auto_broadcast = auto_broadcast
-        self.dispatch = dispatch
+        self.dispatchable = 'fallback' in inspect.signature(self.func).parameters
 
     def __call__(self, *args, **kwargs):
         return self.func(*args, **kwargs)
@@ -79,7 +80,7 @@ def invoke_all(self):
             if self.attrs_valid(**each_kwargs):
                 name = self.name \
                     + ''.join(["{}_{}".format(key, each_kwargs[key]) for key in self.attrs])
-                if self.dispatch is False:
+                if self.dispatchable is False:
                     sch, args = self.func(**each_kwargs)
                     yield sch, args, name
                 else:
@@ -105,7 +106,7 @@ def get_op_name(self, name, args):
 
     def get_config_spaces(self):
         for each_kwargs in self.arg_combination:
-            if self.attrs_valid(**each_kwargs) and self.dispatch is True:
+            if self.attrs_valid(**each_kwargs) and self.dispatchable is True:
                 name = self.name \
                     + ''.join(["{}_{}".format(key, each_kwargs[key]) for key in self.attrs])
                 config_space = autotvm.ConfigSpace()
@@ -120,7 +121,7 @@ def get_binds(self, args):
         return None
 
 
-def defop(name, target=None, auto_broadcast=False, dispatch=False, **kwargs):
+def defop(name, target=None, auto_broadcast=False, **kwargs):
     """Decorator to define a tvm operator.
     Parameters
     ----------
@@ -141,7 +142,7 @@ def defop(name, target=None, auto_broadcast=False, dispatch=False, **kwargs):
     target = "cpu" if target is None else target
 
     def _defop(func):
-        opdef = OpDef(func, name, target, auto_broadcast, dispatch, **kwargs)
+        opdef = OpDef(func, name, target, auto_broadcast, **kwargs)
         __OP_DEF__.append(opdef)
         return opdef
     return _defop