diff -Nru luminance-hdr-2.4.0/CMakeLists.txt luminance-hdr-2.4.0-fits/CMakeLists.txt
--- luminance-hdr-2.4.0/CMakeLists.txt	2014-01-27 21:20:46.000000000 +0100
+++ luminance-hdr-2.4.0-fits/CMakeLists.txt	2014-11-23 15:27:51.043789452 +0100
@@ -122,13 +122,16 @@
 INCLUDE_DIRECTORIES(${JPEGLIB_INCLUDE_DIR})
 INCLUDE_DIRECTORIES(${LCMS2_INCLUDE_DIR})
 
-FIND_PACKAGE(CCfits)
+OPTION(USE_FITS "Use CCfits." OFF)
+IF(USE_FITS)
+FIND_PACKAGE(CCfits REQUIRED)
 IF(CCFITS_FOUND)
     INCLUDE_DIRECTORIES(${CCFITS_INCLUDE_DIRS})
     SET(LIBS ${LIBS} ${CCFITS_LIBRARIES})
     ADD_DEFINITIONS(-DHAVE_CCFITS)
 ELSE()
-    message(WARNING "CCfits not found! Building without FITS support!")
+    message(FATAL_ERROR "CCfits not found!")
+ENDIF()
 ENDIF()
 
 SET(LIBS ${LIBS} ${OPENEXR_LIBRARIES})