diff --git a/flang/include/flang/Optimizer/Transforms/Passes.h b/flang/include/flang/Optimizer/Transforms/Passes.h
index 402f212387e41..0af32f4f8bc80 100644
--- a/flang/include/flang/Optimizer/Transforms/Passes.h
+++ b/flang/include/flang/Optimizer/Transforms/Passes.h
@@ -52,7 +52,6 @@ namespace fir {
 std::unique_ptr<mlir::Pass> createAffineDemotionPass();
 std::unique_ptr<mlir::Pass>
 createArrayValueCopyPass(fir::ArrayValueCopyOptions options = {});
-std::unique_ptr<mlir::Pass> createCharacterConversionPass();
 std::unique_ptr<mlir::Pass> createExternalNameConversionPass();
 std::unique_ptr<mlir::Pass>
 createExternalNameConversionPass(bool appendUnderscore);
diff --git a/flang/include/flang/Optimizer/Transforms/Passes.td b/flang/include/flang/Optimizer/Transforms/Passes.td
index 88e4321e5b2bc..d64b33211b255 100644
--- a/flang/include/flang/Optimizer/Transforms/Passes.td
+++ b/flang/include/flang/Optimizer/Transforms/Passes.td
@@ -127,7 +127,6 @@ def CharacterConversion : Pass<"character-conversion"> {
     By default the translation is to naively zero-extend or truncate a code
     point to fit the destination size.
   }];
-  let constructor = "::fir::createCharacterConversionPass()";
   let dependentDialects = [ "fir::FIROpsDialect" ];
   let options = [
     Option<"useRuntimeCalls", "use-runtime-calls",
diff --git a/flang/include/flang/Tools/CLOptions.inc b/flang/include/flang/Tools/CLOptions.inc
index a9d8ebc84e2e1..952805f604953 100644
--- a/flang/include/flang/Tools/CLOptions.inc
+++ b/flang/include/flang/Tools/CLOptions.inc
@@ -243,7 +243,7 @@ inline void createDefaultFIROptimizerPassPipeline(
   config.enableRegionSimplification = false;
   pm.addPass(mlir::createCSEPass());
   fir::addAVC(pm, pc.OptLevel);
-  pm.addNestedPass<mlir::func::FuncOp>(fir::createCharacterConversionPass());
+  addNestedPassToAllTopLevelOperations(pm, fir::createCharacterConversion);
   pm.addPass(mlir::createCanonicalizerPass(config));
   pm.addPass(fir::createSimplifyRegionLitePass());
   if (pc.OptLevel.isOptimizingForSpeed()) {
diff --git a/flang/lib/Optimizer/Transforms/CharacterConversion.cpp b/flang/lib/Optimizer/Transforms/CharacterConversion.cpp
index 2e8fc42487a5f..87ea72dbca9bb 100644
--- a/flang/lib/Optimizer/Transforms/CharacterConversion.cpp
+++ b/flang/lib/Optimizer/Transforms/CharacterConversion.cpp
@@ -102,6 +102,9 @@ class CharacterConvertConversion
 class CharacterConversion
     : public fir::impl::CharacterConversionBase<CharacterConversion> {
 public:
+  using fir::impl::CharacterConversionBase<
+      CharacterConversion>::CharacterConversionBase;
+
   void runOnOperation() override {
     CharacterConversionOptions clOpts{useRuntimeCalls.getValue()};
     if (clOpts.runtimeName.empty()) {
@@ -130,7 +133,3 @@ class CharacterConversion
   }
 };
 } // end anonymous namespace
-
-std::unique_ptr<mlir::Pass> fir::createCharacterConversionPass() {
-  return std::make_unique<CharacterConversion>();
-}
diff --git a/flang/test/Driver/bbc-mlir-pass-pipeline.f90 b/flang/test/Driver/bbc-mlir-pass-pipeline.f90
index 2ee832e3c57a6..7a35e26dc478c 100644
--- a/flang/test/Driver/bbc-mlir-pass-pipeline.f90
+++ b/flang/test/Driver/bbc-mlir-pass-pipeline.f90
@@ -17,9 +17,14 @@
 ! CHECK-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 ! CHECK-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
 
+! CHECK-NEXT: Pipeline Collection : ['fir.global', 'func.func', 'omp.declare_reduction']
+! CHECK-NEXT: 'fir.global' Pipeline
+! CHECK-NEXT:   CharacterConversion
 ! CHECK-NEXT: 'func.func' Pipeline
 ! CHECK-NEXT:   ArrayValueCopy
 ! CHECK-NEXT:   CharacterConversion
+! CHECK-NEXT: 'omp.declare_reduction' Pipeline
+! CHECK-NEXT:   CharacterConversion
 
 ! CHECK-NEXT: Canonicalizer
 ! CHECK-NEXT: SimplifyRegionLite
diff --git a/flang/test/Driver/mlir-debug-pass-pipeline.f90 b/flang/test/Driver/mlir-debug-pass-pipeline.f90
index 06957604d7aad..28d70bc152642 100644
--- a/flang/test/Driver/mlir-debug-pass-pipeline.f90
+++ b/flang/test/Driver/mlir-debug-pass-pipeline.f90
@@ -39,9 +39,14 @@
 ! ALL-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 ! ALL-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
 
+! ALL-NEXT: Pipeline Collection : ['fir.global', 'func.func', 'omp.declare_reduction']
+! ALL-NEXT: 'fir.global' Pipeline
+! ALL-NEXT:   CharacterConversion
 ! ALL-NEXT: 'func.func' Pipeline
 ! ALL-NEXT:   ArrayValueCopy
 ! ALL-NEXT:   CharacterConversion
+! ALL-NEXT: 'omp.declare_reduction' Pipeline
+! ALL-NEXT:   CharacterConversion
 
 ! ALL-NEXT: Canonicalizer
 ! ALL-NEXT: SimplifyRegionLite
diff --git a/flang/test/Driver/mlir-pass-pipeline.f90 b/flang/test/Driver/mlir-pass-pipeline.f90
index 0272739aba4d0..41f3c203e4355 100644
--- a/flang/test/Driver/mlir-pass-pipeline.f90
+++ b/flang/test/Driver/mlir-pass-pipeline.f90
@@ -28,9 +28,14 @@
 ! ALL-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 ! ALL-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
 
+! ALL-NEXT: Pipeline Collection : ['fir.global', 'func.func', 'omp.declare_reduction']
+! ALL-NEXT: 'fir.global' Pipeline
+! ALL-NEXT:   CharacterConversion
 ! ALL-NEXT: 'func.func' Pipeline
 ! ALL-NEXT:   ArrayValueCopy
 ! ALL-NEXT:   CharacterConversion
+! ALL-NEXT: 'omp.declare_reduction' Pipeline
+! ALL-NEXT:   CharacterConversion
 
 ! ALL-NEXT: Canonicalizer
 ! ALL-NEXT: SimplifyRegionLite
diff --git a/flang/test/Fir/basic-program.fir b/flang/test/Fir/basic-program.fir
index d4826dd2e4762..7508963a3d515 100644
--- a/flang/test/Fir/basic-program.fir
+++ b/flang/test/Fir/basic-program.fir
@@ -34,9 +34,14 @@ func.func @_QQmain() {
 // PASSES-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 // PASSES-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
 
+// PASSES-NEXT: Pipeline Collection : ['fir.global', 'func.func', 'omp.declare_reduction']
+// PASSES-NEXT: 'fir.global' Pipeline
+// PASSES-NEXT:   CharacterConversion
 // PASSES-NEXT: 'func.func' Pipeline
 // PASSES-NEXT:   ArrayValueCopy
 // PASSES-NEXT:   CharacterConversion
+// PASSES-NEXT: 'omp.declare_reduction' Pipeline
+// PASSES-NEXT:   CharacterConversion
 
 // PASSES-NEXT: Canonicalizer
 // PASSES-NEXT: SimplifyRegionLite