diff --git a/CMakeLists.txt b/CMakeLists.txt
index 220a6a222..17423974d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -48,7 +48,7 @@ if("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
 endif()
 
 # make sure all the necessary submodules have been set up
-if (NOT EXISTS ${dfhack_SOURCE_DIR}/depends/protobuf/CMakeLists.txt OR NOT EXISTS ${dfhack_SOURCE_DIR}/depends/clsocket/CMakeLists.txt)
+if (NOT EXISTS ${dfhack_SOURCE_DIR}/library/xml/codegen.pl OR NOT EXISTS ${dfhack_SOURCE_DIR}/depends/clsocket/CMakeLists.txt)
     message(FATAL_ERROR "Required submodules could not be found! First run 'git submodule init' and 'git submodule update' from the root DFHack directory. (See the section 'Getting the Code' in Compile.html)")
 endif()