diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -259,12 +259,13 @@
   endif()
 endif()
 
+set(CMAKE_STATIC_LIBRARY_PREFIX "lib")
+
 # Build the static library.
 if (LIBCXX_ENABLE_STATIC)
   add_library(cxx_static STATIC ${exclude_from_all} ${LIBCXX_SOURCES} ${LIBCXX_HEADERS})
   target_link_libraries(cxx_static PUBLIC cxx-headers
                                    PRIVATE ${LIBCXX_LIBRARIES})
-  set(CMAKE_STATIC_LIBRARY_PREFIX "lib")
   set_target_properties(cxx_static
     PROPERTIES
       COMPILE_FLAGS "${LIBCXX_COMPILE_FLAGS}"