diff --git a/src/tir/transforms/narrow_datatype.cc b/src/tir/transforms/narrow_datatype.cc
index d5d145653fa3..c2bf27393173 100644
--- a/src/tir/transforms/narrow_datatype.cc
+++ b/src/tir/transforms/narrow_datatype.cc
@@ -293,6 +293,24 @@ class DataTypeRewriter : public StmtExprMutator {
     return StmtExprMutator::VisitExpr_(op);
   }
 
+  PrimExpr VisitExpr_(const SelectNode* op) final {
+    PrimExpr condition = this->VisitExpr(op->condition);
+    PrimExpr true_value = this->VisitExpr(op->true_value);
+    PrimExpr false_value = this->VisitExpr(op->false_value);
+    if (condition.same_as(op->condition) && true_value.same_as(op->true_value) &&
+        false_value.same_as(op->false_value)) {
+      return GetRef<PrimExpr>(op);
+    } else {
+      if (op->true_value.dtype().is_int() && op->false_value.dtype().is_int()) {
+        int bits = std::max(true_value.dtype().bits(), false_value.dtype().bits());
+        DataType dtype = true_value.dtype().with_bits(bits);
+        if (true_value.dtype() != dtype) true_value = cast(dtype, true_value);
+        if (false_value.dtype() != dtype) false_value = cast(dtype, false_value);
+      }
+      return Select(condition, true_value, false_value);
+    }
+  }
+
   PrimExpr VisitExpr_(const RampNode* op) final {
     PrimExpr base = VisitExpr(op->base);
     PrimExpr stride = VisitExpr(op->stride);