diff --git a/lld/MachO/InputFiles.cpp b/lld/MachO/InputFiles.cpp
--- a/lld/MachO/InputFiles.cpp
+++ b/lld/MachO/InputFiles.cpp
@@ -698,7 +698,10 @@
         sym.n_desc & REFERENCED_DYNAMICALLY, sym.n_desc & N_NO_DEAD_STRIP,
         isWeakDefCanBeHidden);
   }
-  assert(!isWeakDefCanBeHidden &&
+  // weak_def_can_be_hidden symbols should not reach this point, however a
+  // private alias to one can, so only assert if a weak_def_can_be_hidden symbol
+  // reaches this point, which is not an alias.
+  assert((!isWeakDefCanBeHidden || sym.n_type & N_INDR) &&
          "weak_def_can_be_hidden on already-hidden symbol?");
   bool includeInSymtab = !isPrivateLabel(name) && !isEhFrameSection(isec);
   return make<Defined>(
diff --git a/lld/test/MachO/weak-def-can-be-hidden.s b/lld/test/MachO/weak-def-can-be-hidden.s
--- a/lld/test/MachO/weak-def-can-be-hidden.s
+++ b/lld/test/MachO/weak-def-can-be-hidden.s
@@ -116,6 +116,9 @@
 _foo:
   retq
 
+# A private alias to a weak_def_can_be_hidden symbol should not raise an error or assertion
+.set l_foo, _foo
+
 #--- weak-foo-pe.s
 .private_extern _foo
 .globl _foo