diff --git a/test/functional/rpc_signer.py b/test/functional/rpc_signer.py
index 5ba0d358350..488682e9591 100755
--- a/test/functional/rpc_signer.py
+++ b/test/functional/rpc_signer.py
@@ -21,7 +21,7 @@ class RPCSignerTest(BitcoinTestFramework):
     def mock_signer_path(self):
         path = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'mocks', 'signer.py')
         if platform.system() == "Windows":
-            return "py " + path
+            return "py -3 " + path
         else:
             return path
 
diff --git a/test/functional/wallet_signer.py b/test/functional/wallet_signer.py
index 3e7c613e555..2735ec17069 100755
--- a/test/functional/wallet_signer.py
+++ b/test/functional/wallet_signer.py
@@ -25,21 +25,21 @@ class WalletSignerTest(BitcoinTestFramework):
     def mock_signer_path(self):
         path = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'mocks', 'signer.py')
         if platform.system() == "Windows":
-            return "py " + path
+            return "py -3 " + path
         else:
             return path
 
     def mock_invalid_signer_path(self):
         path = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'mocks', 'invalid_signer.py')
         if platform.system() == "Windows":
-            return "py " + path
+            return "py -3 " + path
         else:
             return path
 
     def mock_multi_signers_path(self):
         path = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'mocks', 'multi_signers.py')
         if platform.system() == "Windows":
-            return "py " + path
+            return "py -3 " + path
         else:
             return path