diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7767166af..80b56d619 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -160,6 +160,7 @@ cmake_dependent_option(PAS16          "Pro Audio Spectrum 16"
 cmake_dependent_option(SIO_DETECT     "Super I/O Detection Helper"                  ON      "DEV_BRANCH"    OFF)
 cmake_dependent_option(VGAWONDER      "ATI VGA Wonder (ATI-18800)"                  ON      "DEV_BRANCH"    OFF)
 cmake_dependent_option(XL24           "ATI VGA Wonder XL24 (ATI-28800-6)"           ON      "DEV_BRANCH"    OFF)
+cmake_dependent_option(OPL4ML         "OPL4-ML daughterboard"                       ON      "DEV_BRANCH"    OFF)
 
 # Ditto but for Qt
 if(QT)