diff --git a/CMakeLists.txt b/CMakeLists.txt
index 523b90dba08c0f8d8a1513dedb431172da953c31..93f660975df4edac32b30148b55bb0e599d77494 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -344,43 +344,44 @@ ENDIF (NOT TIFF_INCLUDE_DIRS)
 INCLUDE_DIRECTORIES(${TIFF_INCLUDE_DIRS})
 
 # Check if gdal has tiff library
-SET(GDAL_HAS_TIFF 0)
+IF(NOT DEFINED GDAL_HAS_TIFF)
 TRY_COMPILE(GDAL_HAS_TIFF
 ${CMAKE_CURRENT_BINARY_DIR}
 ${CMAKE_CURRENT_SOURCE_DIR}/CMake/TestGDALHasTiff.cxx
 CMAKE_FLAGS "-DINCLUDE_DIRECTORIES:PATH=${TIFF_INCLUDE_DIRS};${GDAL_INCLUDE_DIRS}" "-DLINK_DIRECTORIES:PATH=${GDAL_LIBRARY_DIRS}" "-DLINK_LIBRARIES:STRING=gdal"
 OUTPUT_VARIABLE OUTPUT)
 IF(GDAL_HAS_TIFF)
-MESSAGE("-- Testing if GDAL has tiff    -- yes.")
+MESSAGE(STATUS "Testing if GDAL has tiff    -- yes.")
 SET(TIFF_LIBRARY gdal)
 ELSE(GDAL_HAS_TIFF)
-MESSAGE("-- Testing if GDAL has tiff    -- no.")
+MESSAGE(STATUS "Testing if GDAL has tiff    -- no.")
 FIND_LIBRARY(TIFF_LIBRARY tiff PATHS)
 IF (NOT TIFF_LIBRARY)
 MESSAGE(FATAL_ERROR
          "Cannot find tiff library. Please set TIFF_LIBRARY.")
 ENDIF (NOT TIFF_LIBRARY)
 ENDIF(GDAL_HAS_TIFF)
+ENDIF(NOT DEFINED GDAL_HAS_TIFF)
 
 # Check if gdal has geotiff library
-SET(GDAL_HAS_GEOTIFF 0)
+IF(NOT DEFINED GDAL_HAS_GEOTIFF)
 TRY_COMPILE(GDAL_HAS_GEOTIFF
 ${CMAKE_CURRENT_BINARY_DIR}
 ${CMAKE_CURRENT_SOURCE_DIR}/CMake/TestGDALHasGeoTiff.cxx
 CMAKE_FLAGS "-DINCLUDE_DIRECTORIES:PATH=${GEOTIFF_INCLUDE_DIRS};${GDAL_INCLUDE_DIRS}" "-DLINK_DIRECTORIES:PATH=${GDAL_LIBRARY_DIRS}" "-DLINK_LIBRARIES:STRING=gdal"
 OUTPUT_VARIABLE OUTPUT)
 IF(GDAL_HAS_GEOTIFF)
-MESSAGE("-- Testing if GDAL has geotiff -- yes.")
+MESSAGE(STATUS "Testing if GDAL has geotiff -- yes.")
 SET(GEOTIFF_LIBRARY gdal)
 ELSE(GDAL_HAS_GEOTIFF)
-MESSAGE("-- Testing if GDAL has geotiff -- no.")
+MESSAGE(STATUS "Testing if GDAL has geotiff -- no.")
 FIND_LIBRARY(GEOTIFF_LIBRARY geotiff PATHS)
 IF (NOT GEOTIFF_LIBRARY)
 MESSAGE(FATAL_ERROR
          "Cannot find geotiff library. Please set LIBGEOTIFF_LIBRARY_DIR.")
 ENDIF (NOT GEOTIFF_LIBRARY)
 ENDIF(GDAL_HAS_GEOTIFF)
-
+ENDIF(NOT DEFINED GDAL_HAS_GEOTIFF)
 
 
 #-------------------------------