diff --git a/bin/vyper-run b/bin/vyper-run
index fc2c951..60b32fb 100755
--- a/bin/vyper-run
+++ b/bin/vyper-run
@@ -97,7 +97,7 @@ def get_func_abi(abi, func_name, args):
             # try func name first.
             if candidate_func_abi["name"] == func_name and \
                func_name_count_map[candidate_func_abi['name']] == 1:
-                if len(args) != candidate_func_abi['inputs']:
+                if len(args) != len(candidate_func_abi['inputs']):
                     print('Incorrect arguments for {}'.format(func_name))
                     return
                 else:
diff --git a/setup.py b/setup.py
index df930a3..0b86f74 100644
--- a/setup.py
+++ b/setup.py
@@ -48,7 +48,7 @@ setup(
     install_requires=[
         "py-evm==0.2.0a26",
         "eth-tester==0.1.0b28",
-        "vyper>=0.1.0b2"
+        "vyper==0.1.0b3"
     ],
     setup_requires=['setuptools-markdown'],
     python_requires='>=3.6, <4',