diff --git a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
--- a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
+++ b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
@@ -1860,6 +1860,7 @@
 TEST(CompletionTest, CompletionTokenRange) {
   MockFSProvider FS;
   MockCompilationDatabase CDB;
+  FS.Files["foo/abc/foo.h"] = "";
   ClangdServer Server(CDB, FS, ClangdServer::optsForTest());
 
   constexpr const char *TestCodes[] = {
@@ -1882,7 +1883,14 @@
           Auxilary x;
           x.[[]]^;
         }
-      )cpp"};
+      )cpp",
+      R"cpp(
+        #include "foo/[[a^/]]foo.h"
+      )cpp",
+      R"cpp(
+        #include "foo/abc/[[fo^o.h"]]
+      )cpp",
+      };
   for (const auto &Text : TestCodes) {
     Annotations TestCode(Text);
     auto Results = completions(Server, TestCode.code(), TestCode.point());
diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -29,6 +29,7 @@
 #include "clang/Basic/TokenKinds.h"
 #include "llvm/ADT/None.h"
 #include "llvm/ADT/Optional.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/StringRef.h"
@@ -2092,7 +2093,8 @@
                                      bool IsAngled) {
   // Completion only applies to the filename, after the last slash.
   StringRef PartialPath(PathStart, CompletionPoint - PathStart);
-  auto Slash = PartialPath.find_last_of(LangOpts.MSVCCompat ? "/\\" : "/");
+  llvm::StringRef SlashChars = LangOpts.MSVCCompat ? "/\\" : "/";
+  auto Slash = PartialPath.find_last_of(SlashChars);
   StringRef Dir =
       (Slash == StringRef::npos) ? "" : PartialPath.take_front(Slash);
   const char *StartOfFilename =
@@ -2100,7 +2102,8 @@
   // Code completion filter range is the filename only, up to completion point.
   PP->setCodeCompletionIdentifierInfo(&PP->getIdentifierTable().get(
       StringRef(StartOfFilename, CompletionPoint - StartOfFilename)));
-  // We should replace the characters up to the closing quote, if any.
+  // We should replace the characters up to the closing quote or closest slash,
+  // if any.
   while (CompletionPoint < BufferEnd) {
     char Next = *(CompletionPoint + 1);
     if (Next == 0 || Next == '\r' || Next == '\n')
@@ -2108,7 +2111,10 @@
     ++CompletionPoint;
     if (Next == (IsAngled ? '>' : '"'))
       break;
+    if (llvm::is_contained(SlashChars, Next))
+      break;
   }
+
   PP->setCodeCompletionTokenRange(
       FileLoc.getLocWithOffset(StartOfFilename - BufferStart),
       FileLoc.getLocWithOffset(CompletionPoint - BufferStart));