diff --git a/graphblas/dtypes.py b/graphblas/dtypes.py
index 33dd033a1..fd66ba3b2 100644
--- a/graphblas/dtypes.py
+++ b/graphblas/dtypes.py
@@ -91,6 +91,12 @@ def register_anonymous(dtype, name=None):
         if isinstance(dtype, dict):
             # Allow dtypes such as `{'x': int, 'y': float}` for convenience
             dtype = _np.dtype([(key, lookup_dtype(val).np_type) for key, val in dtype.items()])
+        elif isinstance(dtype, str) and "[" in dtype and dtype.endswith("]"):
+            # Allow dtypes such as `"INT64[3, 4]"` for convenience
+            base_dtype, shape = dtype.split("[", 1)
+            base_dtype = lookup_dtype(base_dtype)
+            shape = _np.lib.format.safe_eval(f"[{shape}")
+            dtype = _np.dtype((base_dtype.np_type, shape))
         else:
             raise
     if dtype in _registry:
diff --git a/graphblas/tests/test_vector.py b/graphblas/tests/test_vector.py
index 73b898ef5..8e010fe0b 100644
--- a/graphblas/tests/test_vector.py
+++ b/graphblas/tests/test_vector.py
@@ -1972,6 +1972,8 @@ def test_udt():
     # arrays as dtypes!
     np_dtype = np.dtype("(3,)uint16")
     udt2 = dtypes.register_anonymous(np_dtype, "has_subdtype")
+    udt2alt = dtypes.register_anonymous("UINT16[3]")
+    assert udt2 == udt2alt
     s = Scalar(udt2)
     s.value = [0, 0, 0]