diff --git a/lld/test/MachO/flat-namespace-interposable.s b/lld/test/MachO/flat-namespace-interposable.s
@@ -0,0 +1,80 @@
+# REQUIRES: x86
+# RUN: rm -rf %t; split-file %s %t
+
+## With -flat_namespace, non-weak extern symbols in dylibs become interposable.
+## Check that we generate the correct bindings for them. The test also includes
+## other symbol types like weak externs to verify we continue to do the same
+## (correct) thing even when `-flat_namespace` is enabled, instead of generating
+## spurious bindings.
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-macos -o %t/foo.o %t/foo.s
+# RUN: %lld -lSystem -flat_namespace -o %t/foo %t/foo.o
+# RUN: %lld -lSystem -dylib -flat_namespace -o %t/foo.dylib %t/foo.o
+# RUN: %lld -lSystem -bundle -flat_namespace -o %t/foo.bundle %t/foo.o
+# RUN: llvm-objdump --macho --bind --lazy-bind --weak-bind %t/foo | FileCheck \
+# RUN:   %s --check-prefix=EXEC --implicit-check-not=_private_extern
+# RUN: llvm-objdump --macho --bind --lazy-bind --weak-bind %t/foo.dylib | \
+# RUN:   FileCheck %s --check-prefix=DYLIB --implicit-check-not=_private_extern
+# RUN: llvm-objdump --macho --bind --lazy-bind --weak-bind %t/foo.bundle | \
+# RUN:   FileCheck %s --check-prefix=DYLIB --implicit-check-not=_private_extern
+
+## Executables with -flat_namespace don't have interposable externs.
+# EXEC:       Bind table:
+# EXEC-NEXT:  segment  section          address  type     addend dylib   symbol
+# EXEC-EMPTY:
+# EXEC-NEXT:  Lazy bind table:
+# EXEC-NEXT:  segment  section          address  dylib    symbol
+# EXEC-EMPTY:
+# EXEC-NEXT:  Weak bind table:
+# EXEC-NEXT:  segment  section          address  type     addend   symbol
+# EXEC-NEXT:  __DATA   __la_symbol_ptr  {{.*}}   pointer       0   _weak_extern
+# EXEC-NEXT:  __DATA   __data           {{.*}}   pointer       0   _weak_extern
+# EXEC-EMPTY:
+
+# DYLIB:       Bind table:
+# DYLIB-NEXT:  segment      section        address  type     addend dylib            symbol
+# DYLIB-DAG:   __DATA       __data         {{.*}}   pointer       0 flat-namespace   _extern
+# DYLIB-DAG:   __DATA       __thread_ptrs  {{.*}}   pointer       0 flat-namespace   _tlv
+# DYLIB-DAG:   __DATA_CONST __got          {{.*}}   pointer       0 flat-namespace   dyld_stub_binder
+# DYLIB-EMPTY:
+# DYLIB-NEXT:  Lazy bind table:
+# DYLIB-NEXT:  segment  section            address  dylib            symbol
+# DYLIB-NEXT:  __DATA   __la_symbol_ptr    {{.*}}   flat-namespace   _extern
+# DYLIB-EMPTY:
+# DYLIB-NEXT:  Weak bind table:
+# DYLIB-NEXT:  segment  section            address  type    addend   symbol
+# DYLIB-NEXT:  __DATA   __la_symbol_ptr    {{.*}}   pointer      0   _weak_extern
+# DYLIB-NEXT:  __DATA   __data             {{.*}}   pointer      0   _weak_extern
+
+#--- foo.s
+
+.globl _main, _extern, _weak_extern, _tlv
+.weak_definition _weak_extern
+.private_extern _private_extern
+
+_extern:
+  retq
+_weak_extern:
+  retq
+_private_extern:
+  retq
+_local:
+  retq
+
+_main:
+  callq _extern
+  callq _weak_extern
+  callq _private_extern
+  callq _local
+  mov _tlv@TLVP(%rip), %rax
+  retq
+
+.data
+.quad _extern
+.quad _weak_extern
+.quad _local
+
+.section __DATA,__thread_vars,thread_local_variables
+_tlv:
+
+.subsections_via_symbols