Index: clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
===================================================================
--- clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
+++ clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
@@ -170,6 +170,7 @@
 
     ScanInstance.getFrontendOpts().GenerateGlobalModuleIndex = false;
     ScanInstance.getFrontendOpts().UseGlobalModuleIndex = false;
+    ScanInstance.getFrontendOpts().ModulesShareFileManager = false;
 
     FileMgr->getFileSystemOpts().WorkingDir = std::string(WorkingDirectory);
     ScanInstance.setFileManager(FileMgr);
Index: clang/test/ClangScanDeps/modules-file-path-isolation.c
===================================================================
--- /dev/null
+++ clang/test/ClangScanDeps/modules-file-path-isolation.c
@@ -0,0 +1,44 @@
+// Ensure that the spelling of a path seen outside a module (e.g. header via
+// symlink) does not leak into the compilation of that module unnecessarily.
+// Note: the spelling of the modulemap path still depends on the includer, since
+// that is the only source of information about it.
+
+// REQUIRES: shell
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+// RUN: sed -e "s|DIR|%/t|g" %t/cdb.json.in > %t/cdb.json
+// RUN: ln -s A.h %t/Z.h
+
+// RUN: clang-scan-deps -compilation-database %t/cdb.json -j 1 -format experimental-full \
+// RUN:   -mode preprocess-dependency-directives -generate-modules-path-args > %t/output
+// RUN: FileCheck %s < %t/output
+
+// CHECK:      "modules": [
+// CHECK-NEXT:   {
+// CHECK:          "file-deps": [
+// CHECK-NEXT:       "{{.*}}A.h",
+// CHECK-NEXT:       "{{.*}}module.modulemap"
+// CHECK-NEXT:     ],
+// CHECK-NEXT:     "name": "A"
+// CHECK-NEXT:   }
+
+//--- cdb.json.in
+[{
+  "directory": "DIR",
+  "command": "clang -fsyntax-only DIR/tu.c -fmodules -fmodules-cache-path=DIR/module-cache -fimplicit-modules -fimplicit-module-maps",
+  "file": "DIR/tu.c"
+}]
+
+//--- module.modulemap
+module A { header "A.h" }
+module B { header "B.h" }
+module C { header "C.h" }
+
+//--- A.h
+
+//--- B.h
+#include "Z.h"
+
+//--- tu.c
+#include "B.h"