diff --git a/clang/test/Modules/Inputs/AddRemoveIrrelevantModuleMap/a.modulemap b/clang/test/Modules/Inputs/AddRemoveIrrelevantModuleMap/a.modulemap
deleted file mode 100644
--- a/clang/test/Modules/Inputs/AddRemoveIrrelevantModuleMap/a.modulemap
+++ /dev/null
@@ -1 +0,0 @@
-module a { }
diff --git a/clang/test/Modules/Inputs/AddRemoveIrrelevantModuleMap/b.modulemap b/clang/test/Modules/Inputs/AddRemoveIrrelevantModuleMap/b.modulemap
deleted file mode 100644
--- a/clang/test/Modules/Inputs/AddRemoveIrrelevantModuleMap/b.modulemap
+++ /dev/null
@@ -1 +0,0 @@
-module b { }
diff --git a/clang/test/Modules/add-remove-irrelevant-module-map.m b/clang/test/Modules/add-remove-irrelevant-module-map.m
--- a/clang/test/Modules/add-remove-irrelevant-module-map.m
+++ b/clang/test/Modules/add-remove-irrelevant-module-map.m
@@ -1,16 +1,30 @@
-// RUN: rm -rf %t
-// RUN: rm -rf %t.mcp
-// RUN: mkdir -p %t
+// RUN: rm -rf %t && mkdir %t
+// RUN: split-file %s %t
 
-// Build without b.modulemap
-// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t.mcp -fdisable-module-hash -fmodule-map-file=%S/Inputs/AddRemoveIrrelevantModuleMap/a.modulemap %s -verify
-// RUN: cp %t.mcp/a.pcm %t/a.pcm
+//--- a.modulemap
+module a {}
 
-// Build with b.modulemap
-// RUN: rm -rf %t.mcp
-// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t.mcp -fdisable-module-hash -fmodule-map-file=%S/Inputs/AddRemoveIrrelevantModuleMap/a.modulemap -fmodule-map-file=%S/Inputs/AddRemoveIrrelevantModuleMap/b.modulemap %s -verify
-// RUN: not diff %t.mcp/a.pcm %t/a.pcm
+//--- b.modulemap
+module b {}
 
+//--- test-simple.m
 // expected-no-diagnostics
-
 @import a;
+
+// Build without b.modulemap:
+//
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t/cache -fdisable-module-hash \
+// RUN:   -fmodule-map-file=%t/a.modulemap %t/test-simple.m -verify
+// RUN: mv %t/cache %t/cache-without-b
+
+// Build with b.modulemap:
+//
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t/cache -fdisable-module-hash \
+// RUN:   -fmodule-map-file=%t/a.modulemap -fmodule-map-file=%t/b.modulemap %t/test-simple.m -verify
+// RUN: mv %t/cache %t/cache-with-b
+
+// Neither PCM file considers 'b.modulemap' an input:
+//
+// RUN: %clang_cc1 -module-file-info %t/cache-without-b/a.pcm | FileCheck %s
+// RUN: %clang_cc1 -module-file-info %t/cache-with-b/a.pcm | FileCheck %s
+// CHECK-NOT: Input file: {{.*}}/b.modulemap