Index: clang-tidy/utils/ExprMutationAnalyzer.cpp
===================================================================
--- clang-tidy/utils/ExprMutationAnalyzer.cpp
+++ clang-tidy/utils/ExprMutationAnalyzer.cpp
@@ -48,7 +48,8 @@
 }
 
 const auto nonConstReferenceType = [] {
-  return referenceType(pointee(unless(isConstQualified())));
+  return hasUnqualifiedDesugaredType(
+      referenceType(pointee(unless(isConstQualified()))));
 };
 
 } // namespace
Index: unittests/clang-tidy/ExprMutationAnalyzerTest.cpp
===================================================================
--- unittests/clang-tidy/ExprMutationAnalyzerTest.cpp
+++ unittests/clang-tidy/ExprMutationAnalyzerTest.cpp
@@ -191,6 +191,24 @@
       match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("g(x)"));
 
+  AST = tooling::buildASTFromCode("typedef int& IntRef;"
+                                  "void g(IntRef); void f() { int x; g(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("g(x)"));
+
+  AST =
+      tooling::buildASTFromCode("template <class T> using TRef = T&;"
+                                "void g(TRef<int>); void f() { int x; g(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("g(x)"));
+
+  AST = tooling::buildASTFromCode(
+      "template <class T> struct identity { using type = T; };"
+      "template <class T, class U = T&> void g(typename identity<U>::type);"
+      "void f() { int x; g<int>(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("g<int>(x)"));
+
   AST = tooling::buildASTFromCode(
       "void f() { struct A {}; A operator+(A&, int); A x; x + 1; }");
   Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
@@ -214,6 +232,25 @@
       match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_FALSE(isMutated(Results, AST.get()));
 
+  AST = tooling::buildASTFromCode("typedef const int& CIntRef;"
+                                  "void g(CIntRef); void f() { int x; g(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
+
+  AST = tooling::buildASTFromCode(
+      "template <class T> using CTRef = const T&;"
+      "void g(CTRef<int>); void f() { int x; g(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
+
+  AST = tooling::buildASTFromCode(
+      "template <class T> struct identity { using type = T; };"
+      "template <class T, class U = const T&>"
+      "void g(typename identity<U>::type);"
+      "void f() { int x; g<int>(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
+
   AST = tooling::buildASTFromCode(
       "void f() { struct A {}; A operator+(const A&, int); A x; x + 1; }");
   Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
@@ -440,22 +477,44 @@
 }
 
 TEST(ExprMutationAnalyzerTest, FollowRefModified) {
-  const auto AST = tooling::buildASTFromCode(
+  auto AST = tooling::buildASTFromCode(
       "void f() { int x; int& r0 = x; int& r1 = r0; int& r2 = r1; "
       "int& r3 = r2; r3 = 10; }");
-  const auto Results =
+  auto Results =
       match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_THAT(mutatedBy(Results, AST.get()),
               ElementsAre("r0", "r1", "r2", "r3", "r3 = 10"));
+
+  AST = tooling::buildASTFromCode(
+      "typedef int& IntRefX;"
+      "using IntRefY = int&;"
+      "void f() { int x; IntRefX r0 = x; IntRefY r1 = r0;"
+      "decltype((x)) r2 = r1; r2 = 10; }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_THAT(mutatedBy(Results, AST.get()),
+              ElementsAre("r0", "r1", "r2", "r2 = 10"));
 }
 
 TEST(ExprMutationAnalyzerTest, FollowRefNotModified) {
-  const auto AST = tooling::buildASTFromCode(
+  auto AST = tooling::buildASTFromCode(
       "void f() { int x; int& r0 = x; int& r1 = r0; int& r2 = r1; "
       "int& r3 = r2; int& r4 = r3; int& r5 = r4;}");
-  const auto Results =
+  auto Results =
       match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_FALSE(isMutated(Results, AST.get()));
+
+  AST = tooling::buildASTFromCode(
+      "void f() { int x; int& r0 = x; const int& r1 = r0;}");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
+
+  AST = tooling::buildASTFromCode(
+      "typedef const int& CIntRefX;"
+      "using CIntRefY = const int&;"
+      "void f() { int x; int& r0 = x; CIntRefX r1 = r0;"
+      "CIntRefY r2 = r1; decltype((r1)) r3 = r2;}");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
 }
 
 TEST(ExprMutationAnalyzerTest, FollowConditionalRefModified) {
@@ -542,12 +601,19 @@
 }
 
 TEST(ExprMutationAnalyzerTest, CastToRefModified) {
-  const auto AST = tooling::buildASTFromCode(
+  auto AST = tooling::buildASTFromCode(
       "void f() { int x; static_cast<int &>(x) = 10; }");
-  const auto Results =
+  auto Results =
       match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_THAT(mutatedBy(Results, AST.get()),
               ElementsAre("static_cast<int &>(x) = 10"));
+
+  AST = tooling::buildASTFromCode(
+      "typedef int& IntRef;"
+      "void f() { int x; static_cast<IntRef>(x) = 10; }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_THAT(mutatedBy(Results, AST.get()),
+              ElementsAre("static_cast<IntRef>(x) = 10"));
 }
 
 TEST(ExprMutationAnalyzerTest, CastToRefNotModified) {
@@ -559,11 +625,17 @@
 }
 
 TEST(ExprMutationAnalyzerTest, CastToConstRef) {
-  const auto AST = tooling::buildASTFromCode(
+  auto AST = tooling::buildASTFromCode(
       "void f() { int x; static_cast<const int&>(x); }");
-  const auto Results =
+  auto Results =
       match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_FALSE(isMutated(Results, AST.get()));
+
+  AST =
+      tooling::buildASTFromCode("typedef const int& CIntRef;"
+                                "void f() { int x; static_cast<CIntRef>(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
 }
 
 TEST(ExprMutationAnalyzerTest, LambdaDefaultCaptureByValue) {
@@ -601,11 +673,17 @@
 }
 
 TEST(ExprMutationAnalyzerTest, RangeForArrayByRefModified) {
-  const auto AST = tooling::buildASTFromCode(
+  auto AST = tooling::buildASTFromCode(
       "void f() { int x[2]; for (int& e : x) e = 10; }");
-  const auto Results =
+  auto Results =
       match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("e", "e = 10"));
+
+  AST = tooling::buildASTFromCode(
+      "typedef int& IntRef;"
+      "void f() { int x[2]; for (IntRef e : x) e = 10; }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("e", "e = 10"));
 }
 
 TEST(ExprMutationAnalyzerTest, RangeForArrayByRefNotModified) {
@@ -625,11 +703,17 @@
 }
 
 TEST(ExprMutationAnalyzerTest, RangeForArrayByConstRef) {
-  const auto AST = tooling::buildASTFromCode(
+  auto AST = tooling::buildASTFromCode(
       "void f() { int x[2]; for (const int& e : x) e; }");
-  const auto Results =
+  auto Results =
       match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_FALSE(isMutated(Results, AST.get()));
+
+  AST = tooling::buildASTFromCode(
+      "typedef const int& CIntRef;"
+      "void f() { int x[2]; for (CIntRef e : x) e; }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
 }
 
 TEST(ExprMutationAnalyzerTest, RangeForNonArrayByRefModified) {