diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9213990..f51cc5e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -224,7 +224,9 @@ set(CMAKECONFIGDIR "${DEFAULT_CMAKEDIR}"
 include_directories(${PROJ4_SOURCE_DIR}/src)
 
 message(STATUS "")
-add_subdirectory(data)
+if(BUILD_PROJ_DATABASE)
+  add_subdirectory(data)
+endif()
 add_subdirectory(include)
 add_subdirectory(src)
 add_subdirectory(man)