diff --git a/clang-tools-extra/clangd/index/CanonicalIncludes.cpp b/clang-tools-extra/clangd/index/CanonicalIncludes.cpp
--- a/clang-tools-extra/clangd/index/CanonicalIncludes.cpp
+++ b/clang-tools-extra/clangd/index/CanonicalIncludes.cpp
@@ -68,9 +68,12 @@
         return false;
       // FIXME(ioeric): resolve the header and store actual file path. For now,
       // we simply assume the written header is suitable to be #included.
-      Includes->addMapping(PP.getSourceManager().getFilename(Range.getBegin()),
-                           isLiteralInclude(Text) ? Text.str()
-                                                  : ("\"" + Text + "\"").str());
+      auto &SM = PP.getSourceManager();
+      auto Filename = SM.getFileEntryForID(SM.getFileID(Range.getBegin()))
+                          ->tryGetRealPathName();
+      Includes->addMapping(Filename, isLiteralInclude(Text)
+                                         ? Text.str()
+                                         : ("\"" + Text + "\"").str());
       return false;
     }