diff --git a/clang-tools-extra/clangd/SemanticHighlighting.cpp b/clang-tools-extra/clangd/SemanticHighlighting.cpp
--- a/clang-tools-extra/clangd/SemanticHighlighting.cpp
+++ b/clang-tools-extra/clangd/SemanticHighlighting.cpp
@@ -523,6 +523,8 @@
 /// e.g. highlights dependent names and 'auto' as the underlying type.
 class CollectExtraHighlightings
     : public RecursiveASTVisitor<CollectExtraHighlightings> {
+  using Base = RecursiveASTVisitor<CollectExtraHighlightings>;
+
 public:
   CollectExtraHighlightings(HighlightingsBuilder &H) : H(H) {}
 
@@ -533,6 +535,22 @@
     return true;
   }
 
+  bool TraverseConstructorInitializer(CXXCtorInitializer *Init) {
+    if (!Init->isMemberInitializer())
+      return Base::TraverseConstructorInitializer(Init);
+    if (const auto Member = Init->getMember()) {
+      const auto MemberType = Member->getType();
+      if (MemberType->isLValueReferenceType() &&
+          !MemberType->getPointeeType().isConstQualified()) {
+        if (const auto Param = dyn_cast<DeclRefExpr>(Init->getInit())) {
+          H.addExtraModifier(Param->getLocation(),
+                             HighlightingModifier::UsedAsMutableReference);
+        }
+      }
+    }
+    return Base::TraverseConstructorInitializer(Init);
+  }
+
   bool VisitCallExpr(CallExpr *E) {
     // Highlighting parameters passed by non-const reference does not really
     // make sense for literals...
diff --git a/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp b/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
--- a/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
+++ b/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
@@ -745,6 +745,15 @@
             int &operator[](int &);
             int operator[](int) const;
         };
+        struct $Class_decl[[ClassWithRefMembers]] {
+          $Class_decl[[ClassWithRefMembers]](int $Parameter_decl[[i]])
+            : $Field[[i1]]($Parameter[[i]]),
+              $Field_readonly[[i2]]($Parameter[[i]]),
+              $Field[[i3]]($Parameter_usedAsMutableReference[[i]]) {}
+          int $Field_decl[[i1]];
+          const int &$Field_decl_readonly[[i2]];
+          int &$Field_decl[[i3]];
+        };
         void $Function_decl[[fun]](int, const int,
                                    int*, const int*,
                                    int&, const int&,