diff --git a/imperative/src/impl/transformations/dtype_promote.cpp b/imperative/src/impl/transformations/dtype_promote.cpp
index 4cdcb0b1..d39b6565 100644
--- a/imperative/src/impl/transformations/dtype_promote.cpp
+++ b/imperative/src/impl/transformations/dtype_promote.cpp
@@ -238,7 +238,7 @@ ValueRefList batch_norm_rule(const OpDef& op, Span<ValueRef> inputs) {
     return imperative::apply(op, inputs);
 }
 
-ValueRefList convolution3d_rule(const OpDef& op, Span<ValueRef> inputs) {
+ValueRefList naive_promote_rule(const OpDef& op, Span<ValueRef> inputs) {
     SmallVector<DType> dtypes = get_value_dtypes(inputs);
     mgb::DType target_dtype = get_promoted_dtype(dtypes);
 
@@ -258,12 +258,13 @@ ValueRefList convolution3d_rule(const OpDef& op, Span<ValueRef> inputs) {
 struct DTypePromoteRuleRegistry {
     DTypePromoteRuleRegistry() {
         register_dtype_promote_rule<Elemwise>(elemwise_rule);
+        register_dtype_promote_rule<Concat>(naive_promote_rule);
         register_dtype_promote_rule<Reduce>(reduce_rule);
         register_dtype_promote_rule<Convolution>(convolution_rule);
         register_dtype_promote_rule<ConvolutionBackwardData>(convolution_backward_rule);
         register_dtype_promote_rule<BatchNorm>(batch_norm_rule);
-        register_dtype_promote_rule<Convolution3D>(convolution3d_rule);
-        register_dtype_promote_rule<Convolution3DBackwardData>(convolution3d_rule);
+        register_dtype_promote_rule<Convolution3D>(naive_promote_rule);
+        register_dtype_promote_rule<Convolution3DBackwardData>(naive_promote_rule);
     }
 } register_helper;