diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index 09a9b62ce4cd3..8a5b2792661da 100644
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -63,6 +63,12 @@ if (C_SUPPORTS_NODEFAULTLIBS_FLAG)
                         moldname mingwex msvcrt)
     list(APPEND CMAKE_REQUIRED_LIBRARIES ${MINGW_LIBRARIES})
   endif()
+  check_library_exists(unwind _Unwind_RaiseException "" COMPILER_RT_HAS_LIBUNWIND)
+  if (COMPILER_RT_HAS_LIBUNWIND)
+    # If we're omitting default libraries, we might need to manually link in libunwind.
+    # This can affect whether we detect a statically linked libc++ correctly.
+    list(APPEND CMAKE_REQUIRED_LIBRARIES unwind)
+  endif()
 endif ()
 
 # CodeGen options.