diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -286,6 +286,13 @@
   cxx_add_common_build_flags(cxx_static)
   cxx_set_common_defines(cxx_static)
 
+  if (LIBCXXABI_USE_LLVM_UNWINDER)
+    # If we intend to use the just-built unwinder, add a dependency so that it
+    # gets built, even if we technically aren't going to link it in at this
+    # stage.
+    add_dependencies(cxx_static unwind)
+  endif()
+
   if (LIBCXX_HERMETIC_STATIC_LIBRARY)
     # If the hermetic library doesn't define the operator new/delete functions
     # then its code shouldn't declare them with hidden visibility.  They might