diff --git a/plugins/zynaddsubfx/CMakeLists.txt b/plugins/zynaddsubfx/CMakeLists.txt
index 9f751f38c..77569dd78 100644
--- a/plugins/zynaddsubfx/CMakeLists.txt
+++ b/plugins/zynaddsubfx/CMakeLists.txt
@@ -32,7 +32,11 @@ IF(MINGW_PREFIX)
 	SET(FLTK_SKIP_FLUID TRUE)
 ENDIF()
 
-FIND_PACKAGE(FLTK REQUIRED)
+FIND_PACKAGE(FLTK)
+
+IF(NOT FLTK_FOUND)
+	RETURN()
+ENDIF()
 
 IF(MINGW_PREFIX)
 	SET(FLTK_FLUID_EXECUTABLE "${MINGW_PREFIX}/bin/fluid")