diff --git a/python/triton/language/semantic.py b/python/triton/language/semantic.py
index cd23ea59e9e1..b908b21df478 100644
--- a/python/triton/language/semantic.py
+++ b/python/triton/language/semantic.py
@@ -1133,6 +1133,10 @@ def reduce_impl(input: tl.tensor, axis: int, builder: ir.builder, name: str,
 
     # get result type
     shape = input.type.shape
+
+    rank = len(shape)
+    assert 0 <= axis < rank, f"axis (v={axis}) is out of range, should be within [0, {rank})"
+
     ret_shape = []
     for i, s in enumerate(shape):
         if i != axis: