diff --git a/_pytest/python_api.py b/_pytest/python_api.py
index fe2222059..176aff590 100644
--- a/_pytest/python_api.py
+++ b/_pytest/python_api.py
@@ -66,7 +66,7 @@ class ApproxNumpy(ApproxBase):
         try:
             actual = np.asarray(actual)
         except:
-            raise ValueError("cannot compare '{0}' to numpy.ndarray".format(actual))
+            raise TypeError("cannot compare '{0}' to numpy.ndarray".format(actual))
 
         if actual.shape != self.expected.shape:
             return False