diff --git a/test/ScanDependencies/can_import_with_map.swift b/test/ScanDependencies/can_import_with_map.swift
index 42bd4d1c38efc..e21bf826fe038 100644
--- a/test/ScanDependencies/can_import_with_map.swift
+++ b/test/ScanDependencies/can_import_with_map.swift
@@ -12,11 +12,11 @@
 // RUN: echo "}," >> %/t/inputs/map.json
 // RUN: echo "{" >> %/t/inputs/map.json
 // RUN: echo "\"moduleName\": \"Swift\"," >> %/t/inputs/map.json
-// RUN: echo "\"modulePath\": \"%stdlib_module\"," >> %/t/inputs/map.json
+// RUN: echo "\"modulePath\": \"%/stdlib_module\"" >> %/t/inputs/map.json
 // RUN: echo "}," >> %/t/inputs/map.json
 // RUN: echo "{" >> %/t/inputs/map.json
 // RUN: echo "\"moduleName\": \"SwiftOnoneSupport\"," >> %/t/inputs/map.json
-// RUN: echo "\"modulePath\": \"%ononesupport_module\"," >> %/t/inputs/map.json
+// RUN: echo "\"modulePath\": \"%/ononesupport_module\"" >> %/t/inputs/map.json
 // RUN: echo "}]" >> %/t/inputs/map.json
 
 // RUN: %target-swift-frontend -typecheck %s -explicit-swift-module-map-file %t/inputs/map.json -disable-implicit-swift-modules
diff --git a/test/ScanDependencies/explicit-module-map-forwarding-module.swift b/test/ScanDependencies/explicit-module-map-forwarding-module.swift
index 1e2a7ec047661..5d3c3cfa82c60 100644
--- a/test/ScanDependencies/explicit-module-map-forwarding-module.swift
+++ b/test/ScanDependencies/explicit-module-map-forwarding-module.swift
@@ -22,11 +22,11 @@
 // RUN: echo "}," >> %/t/inputs/map.json
 // RUN: echo "{" >> %/t/inputs/map.json
 // RUN: echo "\"moduleName\": \"Swift\"," >> %/t/inputs/map.json
-// RUN: echo "\"modulePath\": \"%stdlib_module\"," >> %/t/inputs/map.json
+// RUN: echo "\"modulePath\": \"%/stdlib_module\"" >> %/t/inputs/map.json
 // RUN: echo "}," >> %/t/inputs/map.json
 // RUN: echo "{" >> %/t/inputs/map.json
 // RUN: echo "\"moduleName\": \"SwiftOnoneSupport\"," >> %/t/inputs/map.json
-// RUN: echo "\"modulePath\": \"%ononesupport_module\"," >> %/t/inputs/map.json
+// RUN: echo "\"modulePath\": \"%/ononesupport_module\"" >> %/t/inputs/map.json
 // RUN: echo "}]" >> %/t/inputs/map.json
 
 // RUN: %target-swift-ide-test -print-module-comments -module-to-print=Foo -enable-swiftsourceinfo -source-filename %s -explicit-swift-module-map-file %t/inputs/map.json | %FileCheck %s
diff --git a/test/ScanDependencies/explicit-module-map.swift b/test/ScanDependencies/explicit-module-map.swift
index 401014da2d894..821a6cfdc847f 100644
--- a/test/ScanDependencies/explicit-module-map.swift
+++ b/test/ScanDependencies/explicit-module-map.swift
@@ -13,11 +13,11 @@
 // RUN: echo "}," >> %/t/inputs/map.json
 // RUN: echo "{" >> %/t/inputs/map.json
 // RUN: echo "\"moduleName\": \"Swift\"," >> %/t/inputs/map.json
-// RUN: echo "\"modulePath\": \"%stdlib_module\"," >> %/t/inputs/map.json
+// RUN: echo "\"modulePath\": \"%/stdlib_module\"" >> %/t/inputs/map.json
 // RUN: echo "}," >> %/t/inputs/map.json
 // RUN: echo "{" >> %/t/inputs/map.json
 // RUN: echo "\"moduleName\": \"SwiftOnoneSupport\"," >> %/t/inputs/map.json
-// RUN: echo "\"modulePath\": \"%ononesupport_module\"," >> %/t/inputs/map.json
+// RUN: echo "\"modulePath\": \"%/ononesupport_module\"" >> %/t/inputs/map.json
 // RUN: echo "}]" >> %/t/inputs/map.json
 
 // RUN: %target-swift-ide-test -print-module-comments -module-to-print=Foo -enable-swiftsourceinfo -source-filename %s -explicit-swift-module-map-file %t/inputs/map.json | %FileCheck %s
diff --git a/test/lit.cfg b/test/lit.cfg
index e6973ebf5ae1e..e15dbbf6b77a7 100644
--- a/test/lit.cfg
+++ b/test/lit.cfg
@@ -1440,24 +1440,28 @@ config.substitutions.append(('%module-target-future', target_future))
 config.substitutions.append(('%target-sdk-name', config.target_sdk_name))
 
 # Add 'stdlib_dir' as the path to the stdlib resource directory
-stdlib_dir = config.swift_lib_dir + "/swift/"
-if platform.system() == 'Linux':
-    stdlib_dir += config.target_sdk_name + "/" + run_cpu
+stdlib_dir = os.path.join(config.swift_lib_dir, "swift")
+if platform.system() == 'Linux' or platform.system() == 'Windows':
+    stdlib_dir = os.path.join(stdlib_dir, config.target_sdk_name, run_cpu)
 else:
-    stdlib_dir += config.target_sdk_name
+    stdlib_dir = os.path.join(stdlib_dir, config.target_sdk_name)
 config.substitutions.append(('%stdlib_dir', stdlib_dir))
 
 # Add 'stdlib_module' as the path to the stdlib .swiftmodule file
-stdlib_module = stdlib_dir + "/Swift.swiftmodule"
+stdlib_module = os.path.join(stdlib_dir, "Swift.swiftmodule")
 if platform.system() == 'Darwin':
-    stdlib_module += "/" + target_specific_module_triple + ".swiftmodule"
+    stdlib_module = os.path.join(stdlib_module, target_specific_module_triple + ".swiftmodule")
 config.substitutions.append(('%stdlib_module', stdlib_module))
+config.substitutions.append(('%/stdlib_module',
+                             '/'.join(os.path.normpath(stdlib_module).split(os.sep))))
 
 # Add 'ononesupport_module' as the path to the SwiftOnoneSupport .swiftmodule file
-ononesupport_module = stdlib_dir + "/SwiftOnoneSupport.swiftmodule"
+ononesupport_module = os.path.join(stdlib_dir, "SwiftOnoneSupport.swiftmodule")
 if platform.system() == 'Darwin':
-    ononesupport_module += "/" + target_specific_module_triple + ".swiftmodule"
-config.substitutions.append(('%ononesupport_module', ononesupport_module))    
+    ononesupport_module = os.path.join(ononesupport_module, target_specific_module_triple + ".swiftmodule")
+config.substitutions.append(('%ononesupport_module', ononesupport_module))
+config.substitutions.append(('%/ononesupport_module',
+                             '/'.join(os.path.normpath(ononesupport_module).split(os.sep))))
 
 # Different OS's require different prefixes for the environment variables to be
 # propagated to the calling contexts.