diff --git a/mlir/lib/Dialect/Func/Transforms/DuplicateFunctionElimination.cpp b/mlir/lib/Dialect/Func/Transforms/DuplicateFunctionElimination.cpp
--- a/mlir/lib/Dialect/Func/Transforms/DuplicateFunctionElimination.cpp
+++ b/mlir/lib/Dialect/Func/Transforms/DuplicateFunctionElimination.cpp
@@ -9,7 +9,8 @@
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/Dialect/Func/Transforms/Passes.h"
 
-namespace mlir {
+using namespace mlir;
+
 namespace {
 
 #define GEN_PASS_DEF_DUPLICATEFUNCTIONELIMINATIONPASS
@@ -21,9 +22,8 @@
     : public llvm::DenseMapInfo<func::FuncOp> {
 
   static unsigned getHashValue(const func::FuncOp cFunc) {
-    if (!cFunc) {
+    if (!cFunc)
       return DenseMapInfo<func::FuncOp>::getHashValue(cFunc);
-    }
 
     // Aggregate attributes, ignoring the symbol name.
     llvm::hash_code hash = {};
@@ -49,28 +49,23 @@
   }
 
   static bool isEqual(const func::FuncOp cLhs, const func::FuncOp cRhs) {
-    if (cLhs == cRhs) {
+    if (cLhs == cRhs)
       return true;
-    }
     if (cLhs == getTombstoneKey() || cLhs == getEmptyKey() ||
-        cRhs == getTombstoneKey() || cRhs == getEmptyKey()) {
+        cRhs == getTombstoneKey() || cRhs == getEmptyKey())
       return false;
-    }
 
     // Check attributes equivalence, ignoring the symbol name.
-    if (cLhs->getAttrDictionary().size() != cRhs->getAttrDictionary().size()) {
+    if (cLhs->getAttrDictionary().size() != cRhs->getAttrDictionary().size())
       return false;
-    }
     func::FuncOp lhs = const_cast<func::FuncOp &>(cLhs);
     StringAttr symNameAttrName = lhs.getSymNameAttrName();
     for (NamedAttribute namedAttr : cLhs->getAttrs()) {
       StringAttr attrName = namedAttr.getName();
-      if (attrName == symNameAttrName) {
+      if (attrName == symNameAttrName)
         continue;
-      }
-      if (namedAttr.getValue() != cRhs->getAttr(attrName)) {
+      if (namedAttr.getValue() != cRhs->getAttr(attrName))
         return false;
-      }
     }
 
     // Compare inner workings.
@@ -88,37 +83,32 @@
       DuplicateFunctionEliminationPass>::DuplicateFunctionEliminationPassBase;
 
   void runOnOperation() override {
-    auto module = getOperation();
-
-    // Find unique representant per equivalent func ops.
-    DenseSet<func::FuncOp, DuplicateFuncOpEquivalenceInfo> uniqueFuncOps;
-    DenseMap<StringAttr, func::FuncOp> getRepresentant;
-    DenseSet<func::FuncOp> toBeErased;
-    module.walk([&](func::FuncOp f) {
-      auto [repr, inserted] = uniqueFuncOps.insert(f);
-      getRepresentant[f.getSymNameAttr()] = *repr;
-      if (!inserted) {
-        toBeErased.insert(f);
+
+    getOperation().walk([](ModuleOp module) {
+      // Find unique representant per equivalent func ops.
+      DenseSet<func::FuncOp, DuplicateFuncOpEquivalenceInfo> uniqueFuncOps;
+      DenseMap<StringAttr, func::FuncOp> getRepresentant;
+      for (Operation &op : module.getBody()->getOperations()) {
+        auto f = llvm::dyn_cast<func::FuncOp>(op);
+        if (!f)
+          continue;
+        auto [repr, inserted] = uniqueFuncOps.insert(f);
+        getRepresentant[f.getSymNameAttr()] = *repr;
       }
-    });
 
-    // Update call ops to call unique func op representants.
-    module.walk([&](func::CallOp callOp) {
-      func::FuncOp callee = getRepresentant[callOp.getCalleeAttr().getAttr()];
-      callOp.setCallee(callee.getSymName());
+      // Update call ops to call unique func op representants.
+      module.walk([&](func::CallOp callOp) {
+        if (callOp->getParentOfType<ModuleOp>() != module)
+          return;
+        func::FuncOp callee = getRepresentant[callOp.getCalleeAttr().getAttr()];
+        callOp.setCallee(callee.getSymName());
+      });
     });
-
-    // Erase redundant func ops.
-    for (auto it : toBeErased) {
-      it.erase();
-    }
   }
 };
 
 } // namespace
 
-std::unique_ptr<Pass> mlir::func::createDuplicateFunctionEliminationPass() {
+std::unique_ptr<Pass> func::createDuplicateFunctionEliminationPass() {
   return std::make_unique<DuplicateFunctionEliminationPass>();
 }
-
-} // namespace mlir
diff --git a/mlir/test/Dialect/Func/duplicate-function-elimination.mlir b/mlir/test/Dialect/Func/duplicate-function-elimination.mlir
--- a/mlir/test/Dialect/Func/duplicate-function-elimination.mlir
+++ b/mlir/test/Dialect/Func/duplicate-function-elimination.mlir
@@ -20,11 +20,11 @@
   return %2 : tensor<f32>
 }
 
-// CHECK:     @identity
-// CHECK-NOT: @also_identity
-// CHECK-NOT: @yet_another_identity
-// CHECK:     @user
-// CHECK-3:     call @identity
+// CHECK:   @identity
+// CHECK:   @also_identity
+// CHECK:   @yet_another_identity
+// CHECK:   @user
+// CHECK-3:   call @identity
 
 // -----
 
@@ -56,12 +56,12 @@
  return %3 : f32
 }
 
-// CHECK:     @add_lr
-// CHECK-NOT: @also_add_lr
-// CHECK-NOT: @add_rl
-// CHECK-NOT: @also_add_rl
-// CHECK:     @user
-// CHECK-4:     call @add_lr
+// CHECK:   @add_lr
+// CHECK:   @also_add_lr
+// CHECK:   @add_rl
+// CHECK:   @also_add_rl
+// CHECK:   @user
+// CHECK-4:   call @add_lr
 
 // -----
 
@@ -99,12 +99,12 @@
  return %2 : f32
 }
 
-// CHECK:     @ite
-// CHECK-NOT: @also_ite
-// CHECK:     @reverse_ite
-// CHECK:     @user
-// CHECK-2:     call @ite
-// CHECK:       call @reverse_ite
+// CHECK:   @ite
+// CHECK:   @also_ite
+// CHECK:   @reverse_ite
+// CHECK:   @user
+// CHECK-2:   call @ite
+// CHECK:     call @reverse_ite
 
 // -----
 
@@ -359,9 +359,56 @@
   return %0, %1, %2 : f32, f32, f32
 }
 
-// CHECK:     @deep_tree
-// CHECK-NOT: @also_deep_tree
-// CHECK:     @reverse_deep_tree
-// CHECK:     @user
-// CHECK-2:     call @deep_tree
-// CHECK:       call @reverse_deep_tree
+// CHECK:   @deep_tree
+// CHECK:   @also_deep_tree
+// CHECK:   @reverse_deep_tree
+// CHECK:   @user
+// CHECK-2:   call @deep_tree
+// CHECK:     call @reverse_deep_tree
+
+// -----
+
+module {
+
+  func.func @inner_identity(%arg0: tensor<f32>) -> tensor<f32> {
+    return %arg0 : tensor<f32>
+  }
+
+  func.func @also_inner_identity(%arg0: tensor<f32>) -> tensor<f32> {
+    return %arg0 : tensor<f32>
+  }
+
+  func.func @inner_user(%arg0: tensor<f32>) -> tensor<f32> {
+    %0 = call @inner_identity(%arg0) : (tensor<f32>) -> tensor<f32>
+    %1 = call @also_inner_identity(%0) : (tensor<f32>) -> tensor<f32>
+    return %1 : tensor<f32>
+  }
+
+}
+
+func.func @identity(%arg0: tensor<f32>) -> tensor<f32> {
+  return %arg0 : tensor<f32>
+}
+
+func.func @also_identity(%arg0: tensor<f32>) -> tensor<f32> {
+  return %arg0 : tensor<f32>
+}
+
+func.func @user(%arg0: tensor<f32>) -> tensor<f32> {
+  %0 = call @identity(%arg0) : (tensor<f32>) -> tensor<f32>
+  %1 = call @also_identity(%0) : (tensor<f32>) -> tensor<f32>
+  return %1 : tensor<f32>
+}
+
+// CHECK: module 
+// CHECK:   module
+// CHECK:     @inner_identity
+// CHECK:     @also_inner_identity
+// CHECK:     @inner_user
+// CHECK:       call @inner_identity
+// CHECK:       call @inner_identity
+// CHECK:   @identity
+// CHECK:   @also_identity
+// CHECK:   @user
+// CHECK:     call @identity
+// CHECK:     call @identity