diff --git a/clang-tools-extra/clangd/IncludeCleaner.cpp b/clang-tools-extra/clangd/IncludeCleaner.cpp
--- a/clang-tools-extra/clangd/IncludeCleaner.cpp
+++ b/clang-tools-extra/clangd/IncludeCleaner.cpp
@@ -136,22 +136,33 @@
 }
 
 std::vector<include_cleaner::SymbolReference>
-collectMacroReferences(ParsedAST &AST) {
+convertMacroReferences(ParsedAST &AST) {
   const auto &SM = AST.getSourceManager();
-  //  FIXME: !!this is a hacky way to collect macro references.
-  std::vector<include_cleaner::SymbolReference> Macros;
   auto &PP = AST.getPreprocessor();
-  for (const syntax::Token &Tok :
-       AST.getTokens().spelledTokens(SM.getMainFileID())) {
-    auto Macro = locateMacroAt(Tok, PP);
-    if (!Macro)
-      continue;
-    if (auto DefLoc = Macro->Info->getDefinitionLoc(); DefLoc.isValid())
-      Macros.push_back(
-          {Tok.location(),
-           include_cleaner::Macro{/*Name=*/PP.getIdentifierInfo(Tok.text(SM)),
-                                  DefLoc},
-           include_cleaner::RefType::Explicit});
+  std::vector<include_cleaner::SymbolReference> Macros;
+  for (const auto &MAndRefs : AST.getMacros().MacroRefs) {
+    for (const auto &Ref : MAndRefs.second) {
+      auto L = sourceLocationInMainFile(SM, Ref.Rng.start);
+      if (!L) {
+        llvm::consumeError(L.takeError());
+        continue;
+      }
+      if (const auto *Tok =
+             AST.getTokens().spelledTokenAt(*L)) {
+        auto Macro = locateMacroAt(*Tok, PP);
+        if (!Macro)
+          continue;
+
+        if (auto DefLoc = Macro->Info->getDefinitionLoc(); DefLoc.isValid())
+          Macros.push_back(
+              {Tok->location(),
+               include_cleaner::Macro{
+                   /*Name=*/PP.getIdentifierInfo(Tok->text(SM)), DefLoc},
+               Ref.InConditionalDirective
+                   ? include_cleaner::RefType::Implicit
+                   : include_cleaner::RefType::Explicit});
+      }
+    }
   }
   return Macros;
 }
@@ -360,7 +371,7 @@
   const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID());
 
   std::vector<include_cleaner::SymbolReference> Macros =
-      collectMacroReferences(AST);
+      convertMacroReferences(AST);
   std::vector<MissingIncludeDiagInfo> MissingIncludes;
   llvm::DenseSet<IncludeStructure::HeaderID> Used;
   trace::Span Tracer("include_cleaner::walkUsed");
diff --git a/clang-tools-extra/clangd/unittests/IncludeCleanerTests.cpp b/clang-tools-extra/clangd/unittests/IncludeCleanerTests.cpp
--- a/clang-tools-extra/clangd/unittests/IncludeCleanerTests.cpp
+++ b/clang-tools-extra/clangd/unittests/IncludeCleanerTests.cpp
@@ -189,6 +189,10 @@
 #define DEF(X) const Foo *X;
 #define BAZ(X) const X x
 
+// No missing include insertion for ambiguous macro refs.
+#if defined(FOO)
+#endif
+
   void foo() {
     $b[[b]]();