diff --git a/lld/test/MachO/treat-undef-sym.s b/lld/test/MachO/treat-undef-sym.s
--- a/lld/test/MachO/treat-undef-sym.s
+++ b/lld/test/MachO/treat-undef-sym.s
@@ -1,28 +1,33 @@
 # REQUIRES: x86
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-macos %s -o %t.o
-# RUN: not %lld -undefined bogus -o /dev/null %t.o 2>&1 | \
+# RUN: not %lld -dylib -undefined bogus -o /dev/null %t.o 2>&1 | \
 # RUN:     FileCheck %s -check-prefix=UNKNOWN
-# RUN: not %lld -undefined error -o /dev/null %t.o 2>&1 | \
+# RUN: not %lld -dylib -undefined error -o /dev/null %t.o 2>&1 | \
 # RUN:     FileCheck %s -check-prefix=ERROR
+## Since the undefined symbol is in dead code, it should not raise an error if
+## -dead_strip is enabled.
+# RUN: %lld -dylib -dead_strip -undefined error -o /dev/null %t.o
 
-# RUN: not %lld -undefined warning -o /dev/null %t.o 2>&1 | \
+# RUN: not %lld -dylib -undefined warning -o /dev/null %t.o 2>&1 | \
 # RUN:     FileCheck %s -check-prefix=INVAL-WARNING
-# RUN: not %lld -undefined suppress -o /dev/null %t.o 2>&1 | \
+# RUN: not %lld -dylib -undefined suppress -o /dev/null %t.o 2>&1 | \
 # RUN:     FileCheck %s -check-prefix=INVAL-SUPPRESS
-# RUN: %lld -undefined dynamic_lookup -lSystem -o %t.out %t.o 2>&1 | count 0
+# RUN: %lld -dylib -undefined dynamic_lookup -lSystem -o %t.out %t.o 2>&1 | count 0
 # RUN: llvm-objdump --macho --lazy-bind %t.out \
 # RUN:     | FileCheck --check-prefix=BIND %s
 
-# RUN: %no_fatal_warnings_lld -lSystem -flat_namespace -undefined warning \
-# RUN:     -o %t.out %t.o 2>&1 | \
+# RUN: %no_fatal_warnings_lld -dylib -lSystem -flat_namespace \
+# RUN:     -undefined warning -o %t.out %t.o 2>&1 | \
 # RUN:     FileCheck %s -check-prefix=WARNING
 # RUN: llvm-objdump --macho --lazy-bind %t.out \
 # RUN:     | FileCheck --check-prefix=BIND %s
-# RUN: %lld -flat_namespace -lSystem -undefined suppress -o %t.out %t.o 2>&1 | count 0
+# RUN: %lld -dylib -flat_namespace -lSystem -undefined suppress -o %t.out %t.o \
+# RUN:     2>&1 | count 0
 # RUN: llvm-objdump --macho --lazy-bind %t.out \
 # RUN:     | FileCheck --check-prefix=BIND %s
-# RUN: %lld -flat_namespace -lSystem -undefined dynamic_lookup -o %t.out %t.o 2>&1 | count 0
+# RUN: %lld -dylib -flat_namespace -lSystem -undefined dynamic_lookup -o \
+# RUN:     %t.out %t.o 2>&1 | count 0
 # RUN: llvm-objdump --macho --lazy-bind %t.out \
 # RUN:     | FileCheck --check-prefix=BIND %s
 
@@ -45,7 +50,6 @@
 # BIND: Lazy bind table:
 # BIND: __DATA   __la_symbol_ptr    0x{{[0-9a-f]*}} flat-namespace   _bar
 
-.globl _main
-_main:
+_dead:
   callq _bar
   ret