diff --git a/lld/MachO/SyntheticSections.cpp b/lld/MachO/SyntheticSections.cpp
--- a/lld/MachO/SyntheticSections.cpp
+++ b/lld/MachO/SyntheticSections.cpp
@@ -627,11 +627,11 @@
 void SymtabSection::emitBeginSourceStab(DWARFUnit *compileUnit) {
   StabsEntry stab(N_SO);
   SmallString<261> dir(compileUnit->getCompilationDir());
-  StringRef sep = sys::path::get_separator();
   // We don't use `path::append` here because we want an empty `dir` to result
   // in an absolute path. `append` would give us a relative path for that case.
-  if (!dir.endswith(sep))
-    dir += sep;
+  // FIXME: This assumes that the source was compiled on a POSIX machine.
+  if (!dir.endswith("/"))
+    dir += "/";
   stab.strx = stringTableSection.addString(
       saver.save(dir + compileUnit->getUnitDIE().getShortName()));
   stabs.emplace_back(std::move(stab));
diff --git a/lld/test/MachO/stabs.s b/lld/test/MachO/stabs.s
--- a/lld/test/MachO/stabs.s
+++ b/lld/test/MachO/stabs.s
@@ -1,5 +1,4 @@
-# REQUIRES: x86, shell
-# UNSUPPORTED: system-windows
+# REQUIRES: x86
 # RUN: rm -rf %t; split-file %s %t
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/test.s -o %t/test.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/foo.s -o %t/foo.o
@@ -10,24 +9,28 @@
 # RUN: llvm-ar rcsU %t/foo.a %t/foo.o
 
 # RUN: %lld -lSystem %t/test.o %t/foo.o %t/no-debug.o -o %t/test
-# RUN: (llvm-objdump --section-headers %t/test; llvm-nm -pa %t/test) | \
-# RUN:   FileCheck %s -DDIR=%t -DFOO_PATH=%t/foo.o
+# RUN: llvm-objdump --section-headers %t/test > %t/out
+# RUN: llvm-nm -pa %t/test >> %t/out
+# RUN: FileCheck %s -DDIR=%t -DFOO_PATH=%t/foo.o < %t/out
 
 ## Check that we emit the right modtime even when the object file is in an
 ## archive.
 # RUN: %lld -lSystem %t/test.o %t/foo.a %t/no-debug.o -o %t/test
-# RUN: (llvm-objdump --section-headers %t/test; llvm-nm -pa %t/test) | \
-# RUN:   FileCheck %s -DDIR=%t -DFOO_PATH=%t/foo.a\(foo.o\)
+# RUN: llvm-objdump --section-headers %t/test > %t/out
+# RUN: llvm-nm -pa %t/test >> %t/out
+# RUN: FileCheck %s -DDIR=%t -DFOO_PATH=%t/foo.a\(foo.o\) < %t/out
 
 ## Check that we emit absolute paths to the object files in our OSO entries
 ## even if our inputs are relative paths.
 # RUN: cd %t && %lld -lSystem test.o foo.o no-debug.o -o test
-# RUN: (llvm-objdump --section-headers %t/test; llvm-nm -pa %t/test) | \
-# RUN:   FileCheck %s -DDIR=%t -DFOO_PATH=%t/foo.o
+# RUN: llvm-objdump --section-headers %t/test > %t/out
+# RUN: llvm-nm -pa %t/test >> %t/out
+# RUN: FileCheck %s -DDIR=%t -DFOO_PATH=%t/foo.o < %t/out
 
 # RUN: cd %t && %lld -lSystem test.o foo.a no-debug.o -o %t/test
-# RUN: (llvm-objdump --section-headers %t/test; llvm-nm -pa %t/test) | \
-# RUN:   FileCheck %s -DDIR=%t -DFOO_PATH=%t/foo.a\(foo.o\)
+# RUN: llvm-objdump --section-headers %t/test > %t/out
+# RUN: llvm-nm -pa %t/test >> %t/out
+# RUN: FileCheck %s -DDIR=%t -DFOO_PATH=%t/foo.a\(foo.o\) < %t/out
 
 # CHECK:       Sections:
 # CHECK-NEXT:  Idx                Name