diff --git a/xls/tools/codegen.cc b/xls/tools/codegen.cc
index d9d0b43b61..a0071cbd87 100644
--- a/xls/tools/codegen.cc
+++ b/xls/tools/codegen.cc
@@ -201,6 +201,11 @@ absl::StatusOr<verilog::CodegenResult> CodegenFromMetadata(
   if (codegen_version == verilog::CodegenOptions::Version::kDefault) {
     codegen_version = verilog::CodegenOptions::Version::kOneDotZero;
   }
+  if (p->ChannelsAreProcScoped()) {
+    // Force Codegen 1.5 if proc-scoped channels were generated during the IR
+    // conversion.
+    codegen_version = verilog::CodegenOptions::Version::kOneDotFive;
+  }
 
   if (codegen_version == verilog::CodegenOptions::Version::kOneDotZero) {
     if (generator_kind == GENERATOR_KIND_COMBINATIONAL) {
diff --git a/xls/tools/codegen_main.cc b/xls/tools/codegen_main.cc
index 2cbcdb200d..ec20832e2f 100644
--- a/xls/tools/codegen_main.cc
+++ b/xls/tools/codegen_main.cc
@@ -73,6 +73,11 @@ absl::Status RealMain(std::string_view ir_path) {
 
   XLS_ASSIGN_OR_RETURN(CodegenFlagsProto codegen_flags_proto,
                        GetCodegenFlags());
+  if (p->ChannelsAreProcScoped()) {
+    // Force Codegen 1.5 if proc-scoped channels were generated during the IR
+    // conversion.
+    codegen_flags_proto.set_codegen_version(CODEGEN_VERSION_ONE_DOT_FIVE);
+  }
   if (codegen_flags_proto.has_reference_residual_data()) {
     return absl::UnimplementedError(
         "Reference residual data is not supported in codegen_main; use "