--- CMakeLists.txt	(revision 22461)
+++ CMakeLists.txt	(working copy)
@@ -926,5 +926,6 @@
 # CTL support
 pkg_check_modules(HARFBUZZ REQUIRED harfbuzz>=0.9.42 harfbuzz-icu)
 pkg_check_modules(ICU REQUIRED icu-uc)
+add_definitions(-DU_USING_ICU_NAMESPACE=1)
 
 
