diff --git a/src/tools/keymap/Jamfile b/src/tools/keymap/Jamfile
index 9f0859a10b..a913884f5c 100644
--- a/src/tools/keymap/Jamfile
+++ b/src/tools/keymap/Jamfile
@@ -11,6 +11,8 @@ local regexSources ;
 local storageSources ;
 
 if $(HOST_PLATFORM) = cygwin || $(HOST_PLATFORM) = sunos {
+	UseHeaders [ FDirName $(HAIKU_TOP) src system libroot posix glibc regex ] ;
+	SubDirCcFlags -D__USE_GNU -DHAVE_STDBOOL_H ;
 	regexSources = regex.c ;
 }
 if $(HOST_PLATFORM) = haiku_host {