diff --git a/Lib/CMake/kll.cmake b/Lib/CMake/kll.cmake
index 0de02bf..80d44c1 100644
--- a/Lib/CMake/kll.cmake
+++ b/Lib/CMake/kll.cmake
@@ -57,9 +57,11 @@ set ( pathname "${PROJECT_SOURCE_DIR}/${ScanModulePath}" )
 if ( NOT EXISTS ${pathname}/${BaseMap}.kll )
 	set ( BaseMap_Args ${BaseMap_Args} ${pathname}/defaultMap.kll )
 	set ( KLL_DEPENDS ${KLL_DEPENDS} ${pathname}/defaultMap.kll )
-else ()
+elseif ( EXISTS "${pathname}/${BaseMap}.kll" )
 	set ( BaseMap_Args ${BaseMap_Args} ${pathname}/${BaseMap}.kll )
 	set ( KLL_DEPENDS ${KLL_DEPENDS} ${pathname}/${BaseMap}.kll )
+else ()
+	message ( FATAL "Could not find '${BaseMap}.kll'" )
 endif ()
 
 #| Configure DefaultMap if specified
@@ -72,9 +74,11 @@ if ( NOT "${DefaultMap}" STREQUAL "" )
 		if ( EXISTS "${PROJECT_BINARY_DIR}/${MAP}.kll" )
 			set ( DefaultMap_Args ${DefaultMap_Args} ${MAP}.kll )
 			set ( KLL_DEPENDS ${KLL_DEPENDS} ${PROJECT_BINARY_DIR}/${MAP}.kll )
-		else ()
+		elseif ( EXISTS "${PROJECT_SOURCE_DIR}/kll/layouts/${MAP}.kll" )
 			set ( DefaultMap_Args ${DefaultMap_Args} ${PROJECT_SOURCE_DIR}/kll/layouts/${MAP}.kll )
 			set ( KLL_DEPENDS ${KLL_DEPENDS} ${PROJECT_SOURCE_DIR}/kll/layouts/${MAP}.kll )
+		else ()
+			message ( FATAL "Could not find '${MAP}.kll'" )
 		endif ()
 	endforeach ()
 endif ()
@@ -92,9 +96,11 @@ if ( NOT "${PartialMaps}" STREQUAL "" )
 			if ( EXISTS "${PROJECT_BINARY_DIR}/${MAP_PART}.kll" )
 				set ( PartialMap_Args ${PartialMap_Args} ${MAP_PART}.kll )
 				set ( KLL_DEPENDS ${KLL_DEPENDS} ${PROJECT_BINARY_DIR}/${MAP_PART}.kll )
-			else ()
+			elseif ( EXISTS "${PROJECT_SOURCE_DIR}/kll/layouts/${MAP_PART}.kll" )
 				set ( PartialMap_Args ${PartialMap_Args} ${PROJECT_SOURCE_DIR}/kll/layouts/${MAP_PART}.kll )
 				set ( KLL_DEPENDS ${KLL_DEPENDS} ${PROJECT_SOURCE_DIR}/kll/layouts/${MAP_PART}.kll )
+			else ()
+				message ( FATAL "Could not find '${MAP_PART}.kll'" )
 			endif ()
 		endforeach ()
 	endforeach ()