diff --git a/pyopencl/__init__.py b/pyopencl/__init__.py
index 787369ace9a3ac8503c8eeabac98fe26971b8cbc..24ec66b6b9261736c97c782e5f9e5a8e49af2aca 100644
--- a/pyopencl/__init__.py
+++ b/pyopencl/__init__.py
@@ -850,7 +850,7 @@ def _add_functionality():
                 # argument to internal function
 
                 gen(
-                        "buf = pack('{arg_char}', long({arg_var})"
+                        "buf = pack('{arg_char}', long({arg_var}))"
                         .format(arg_char=arg_dtype.char, arg_var=arg_var))
                 self._generate_buffer_arg_setter(gen, cl_arg_idx, "buf")
                 cl_arg_idx += 1