Index: clangd/index/SymbolCollector.cpp
===================================================================
--- clangd/index/SymbolCollector.cpp
+++ clangd/index/SymbolCollector.cpp
@@ -290,6 +290,18 @@
     index::IndexDataConsumer::ASTNodeInfo ASTNode) {
   assert(ASTCtx && PP.get() && "ASTContext and Preprocessor must be set.");
   assert(CompletionAllocator && CompletionTUInfo);
+  assert(ASTNode.OrigD);
+  // If OrigD is an declaration associated with a friend declaration and it's
+  // not a definition, skip it. Note that OrigD is the occurrence that the
+  // collector is currently visiting.
+  if ((ASTNode.OrigD->getFriendObjectKind() !=
+       Decl::FriendObjectKind::FOK_None) &&
+      !(Roles & static_cast<unsigned>(index::SymbolRole::Definition)))
+    return true;
+  // A declaration created for a friend declaration should not be used as the
+  // canonical declaration in the index.
+  if (D->getFriendObjectKind() != Decl::FriendObjectKind::FOK_None)
+    D = ASTNode.OrigD;
   const NamedDecl *ND = llvm::dyn_cast<NamedDecl>(D);
   if (!ND)
     return true;
Index: unittests/clangd/SymbolCollectorTests.cpp
===================================================================
--- unittests/clangd/SymbolCollectorTests.cpp
+++ unittests/clangd/SymbolCollectorTests.cpp
@@ -812,6 +812,31 @@
                                    QName("nx::Kind"), QName("nx::Kind_Fine")));
 }
 
+TEST_F(SymbolCollectorTest, DoNotIndexSymbolsInFriendDecl) {
+  Annotations Header(R"(
+    namespace nx {
+      class $z[[Z]] {};
+      class X {
+        friend class Y;
+        friend class Z;
+        friend void foo();
+        friend void $bar[[bar]]() {}
+      };
+      class $y[[Y]] {};
+      void $foo[[foo]]();
+    }
+  )");
+  runSymbolCollector(Header.code(), /*Main=*/"");
+
+  EXPECT_THAT(Symbols,
+              UnorderedElementsAre(
+                  QName("nx"), QName("nx::X"),
+                  AllOf(QName("nx::Y"), DeclRange(Header.range("y"))),
+                  AllOf(QName("nx::Z"), DeclRange(Header.range("z"))),
+                  AllOf(QName("nx::foo"), DeclRange(Header.range("foo"))),
+                  AllOf(QName("nx::bar"), DeclRange(Header.range("bar")))));
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang