diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -353,9 +353,10 @@
     return nullptr;
 
   const MCSymbol &Aliasee = SymRef->getSymbol();
-  if (!Aliasee.isUndefined())
+  if (Aliasee.isUndefined() || Aliasee.isExternal())
+    return GetOrCreateCOFFSymbol(&Aliasee);
+  else
     return nullptr;
-  return GetOrCreateCOFFSymbol(&Aliasee);
 }
 
 /// This function takes a symbol data object from the assembler
diff --git a/llvm/test/MC/COFF/weak.s b/llvm/test/MC/COFF/weak.s
--- a/llvm/test/MC/COFF/weak.s
+++ b/llvm/test/MC/COFF/weak.s
@@ -77,17 +77,7 @@
 // CHECK-NEXT:   StorageClass:   WeakExternal
 // CHECK-NEXT:   AuxSymbolCount: 1
 // CHECK-NEXT:   AuxWeakExternal {
-// CHECK-NEXT:     Linked: .weak._test_weak_alias.default
+// CHECK-NEXT:     Linked: _main
 // CHECK-NEXT:      Search: Alias
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
-
-// CHECK:      Symbol {
-// CHECK:        Name: .weak._test_weak_alias.default._main
-// CHECK-NEXT:   Value: 0
-// CHECK-NEXT:   Section: .text
-// CHECK-NEXT:   BaseType: Null
-// CHECK-NEXT:   ComplexType: Null
-// CHECK-NEXT:   StorageClass: External
-// CHECK-NEXT:   AuxSymbolCount: 0
-// CHECK-NEXT: }