diff --git a/Testing/CMakeLists.txt b/Testing/CMakeLists.txt
index 4d34f46fffadc81f6add1ea1117a2f1760b051aa..0f07a1192bbbd62e8316e550117a59137a85e9e7 100644
--- a/Testing/CMakeLists.txt
+++ b/Testing/CMakeLists.txt
@@ -88,7 +88,7 @@ ELSE(OTB_BINARY_DIR)
     INCLUDE(${OTB_USE_FILE})
     ADD_SUBDIRECTORY(Code)
   ELSE(OTB_FOUND)
-    MESSAGE("OTB not found.  Please set OTB_DIR")
+    MESSAGE(FATAL_ERROR "OTB not found.  Please set OTB_DIR")
   ENDIF(OTB_FOUND)
   
   CONFIGURE_FILE(../CMake/CTestCustom.cmake.in CTestCustom.cmake)