diff --git a/pyopencl/array.py b/pyopencl/array.py
index 450aec8e14255dd2f5d08226c0265b3ae2265a4c..30555a9f0aff4def6306e758f3d433eecdfdfb94 100644
--- a/pyopencl/array.py
+++ b/pyopencl/array.py
@@ -76,22 +76,22 @@ def _get_common_dtype(obj1, obj2):
 
 @decorator
 def elwise_kernel_runner(kernel_getter, *args, **kwargs):
-    """Take a kernel getter of the same signature as the kernel 
+    """Take a kernel getter of the same signature as the kernel
     and return a function that invokes that kernel.
 
     Assumes that the zeroth entry in *args* is an :class:`Array`.
     """
 
-    knl = kernel_getter(*args)
-
+    # The decorators module converts kwargs to positional arguments,
+    # so we pop the queue argument first
+    args = list(args)
     repr_ary = args[0]
-    assert isinstance(repr_ary, Array)
+    queue = args.pop() or repr_ary.queue
 
-    queue = kwargs.pop("queue", None) or repr_ary.queue
     gs, ls = repr_ary.get_sizes(queue)
+    knl = kernel_getter(*args)
 
-    if kwargs:
-        raise TypeError("only the 'queue' keyword argument is supported")
+    assert isinstance(repr_ary, Array)
 
     actual_args = []
     for arg in args:
@@ -205,20 +205,21 @@ class Array(object):
         raise TypeError("pyopencl arrays are not hashable.")
 
     # kernel invocation wrappers ----------------------------------------------
-    @elwise_kernel_runner
     @staticmethod
+    @elwise_kernel_runner
     def _axpbyz(out, afac, a, bfac, b, queue=None):
         """Compute ``out = selffac * self + otherfac*other``,
         where `other` is a vector.."""
-        assert self.shape == other.shape
+        assert out.shape == a.shape
 
         return elementwise.get_axpbyz_kernel(
-                self.context, self.dtype, other.dtype, out.dtype)
+                out.context, a.dtype, b.dtype, out.dtype)
 
+    @staticmethod
     @elwise_kernel_runner
-    def _axpbz(self, out, selffac, other, queue=None):
-        """Compute ``out = selffac * self + other``, where `other` is a scalar."""
-        return elementwise.get_axpbz_kernel(self.context, self.dtype)
+    def _axpbz(out, afac, a, other, queue=None):
+        """Compute ``out = afac * a + other``, where `other` is a scalar."""
+        return elementwise.get_axpbz_kernel(out.context, out.dtype)
 
     @elwise_kernel_runner
     def _elwise_multiply(self, out, other, queue=None):
@@ -297,7 +298,7 @@ class Array(object):
 
         if isinstance(other, Array):
             result = self._new_like_me(_get_common_dtype(self, other))
-            self._axpbyz(result, 1, other, -1)
+            self._axpbyz(result, 1, self, -1, other)
             return result
         else:
             if other == 0: