diff --git a/src/transform/storage_rewrite.cc b/src/transform/storage_rewrite.cc
index 40973f39a..91ca0d347 100644
--- a/src/transform/storage_rewrite.cc
+++ b/src/transform/storage_rewrite.cc
@@ -1094,6 +1094,10 @@ class StoragePlanRewriter : public StmtExprMutator {
       return NewAlloc(op, attach_scope, scope, const_nbits);
     }
 
+    if (scope.tag == ".var") {
+      return NewAlloc(op, attach_scope, scope, const_nbits);
+    }
+
     if (is_known_size) {
       // constant allocation.
       auto begin = const_free_map_.lower_bound(const_nbits / match_range);
diff --git a/testing/python/issue/test_tilelang_issue_1678.py b/testing/python/issue/test_tilelang_issue_1678.py
new file mode 100644
index 000000000..236800a13
--- /dev/null
+++ b/testing/python/issue/test_tilelang_issue_1678.py
@@ -0,0 +1,30 @@
+import tilelang
+import tilelang.testing
+from tilelang import language as T
+
+
+@tilelang.jit
+def _alloc_var_mixed_dtype_kernel():
+    @T.prim_func
+    def kernel():
+        with T.Kernel(1, 1, threads=1) as (_, _):
+            i = T.alloc_var(T.int32)
+            i = 1
+            tmp_row = T.alloc_local((4,), T.float32)
+            amax_local = T.alloc_var(T.float32)
+            j = i
+            amax_local = T.max(amax_local, tmp_row[j])
+
+    return kernel
+
+
+@tilelang.testing.requires_cuda
+def test_alloc_var_mixed_dtype_codegen():
+    kernel = _alloc_var_mixed_dtype_kernel()
+    source = kernel.get_kernel_source()
+    assert "int i" in source
+    assert "float amax_local" in source
+
+
+if __name__ == "__main__":
+    tilelang.testing.main()