diff --git a/test/test_ops.py b/test/test_ops.py
index 8878af0eb6..48e2d3fc65 100644
--- a/test/test_ops.py
+++ b/test/test_ops.py
@@ -1221,7 +1221,7 @@ class TestOps(unittest.TestCase):
   def test_einsum_shape_check(self):
     a = Tensor.zeros(3,8,10,5)
     b = Tensor.zeros(11,5,13,16,8)
-    with self.assertRaises(AssertionError):
+    with self.assertRaises(RuntimeError):
       Tensor.einsum('pqrs,tuqvr->pstuv',a,b)
 
   def test_einsum_arity_check1(self):
diff --git a/test/unit/test_helpers.py b/test/unit/test_helpers.py
index 2896f60e77..3000ef89ed 100644
--- a/test/unit/test_helpers.py
+++ b/test/unit/test_helpers.py
@@ -93,7 +93,7 @@ class TestMergeDicts(unittest.TestCase):
     assert merge_dicts([a, b]) == {"a": 1, "b": 2, "c": 3}
     assert merge_dicts([a, c]) == a
     assert merge_dicts([a, b, c]) == {"a": 1, "b": 2, "c": 3}
-    with self.assertRaises(AssertionError):
+    with self.assertRaises(RuntimeError):
       merge_dicts([a, d])
 
 class TestStripParens(unittest.TestCase):
diff --git a/tinygrad/helpers.py b/tinygrad/helpers.py
index 94378141de..53ba564de4 100644
--- a/tinygrad/helpers.py
+++ b/tinygrad/helpers.py
@@ -56,7 +56,7 @@ def i2u(bits: int, value: int): return value if value >= 0 else (1<<bits)+value
 def is_numpy_ndarray(x) -> bool: return str(type(x)) == "<class 'numpy.ndarray'>"
 def merge_dicts(ds:Iterable[dict[T,U]]) -> dict[T,U]:
   kvs = set([(k,v) for d in ds for k,v in d.items()])
-  assert len(kvs) == len(set(kv[0] for kv in kvs)), f"cannot merge, {kvs} contains different values for the same key"
+  if len(kvs) != len(set(kv[0] for kv in kvs)): raise RuntimeError(f"{kvs} contains different values for the same key")
   return {k:v for d in ds for k,v in d.items()}
 def partition(itr:Iterable[T], fxn:Callable[[T],bool]) -> tuple[list[T], list[T]]:
   ret:tuple[list[T], list[T]] = ([], [])