Index: kernel/Makefile
===================================================================
--- kernel/Makefile	(revision 247fdeac73871cc6bd13ed2cc6665e081d3ea7cb)
+++ kernel/Makefile	(revision 58168e01ce7842cf23ff1972205eee0da2d3467c)
@@ -87,5 +87,5 @@
 INCLUDES_FLAGS = $(addprefix -I,$(INCLUDES))
 
-DEFS = -DKERNEL -DRELEASE=$(RELEASE) "-DCOPYRIGHT=$(COPYRIGHT)" "-DNAME=$(NAME)" -D__$(BITS)_BITS__ -D__$(ENDIANESS)__
+DEFS = -D_HELENOS_SOURCE -DKERNEL -DRELEASE=$(RELEASE) "-DCOPYRIGHT=$(COPYRIGHT)" "-DNAME=$(NAME)" -D__$(BITS)_BITS__ -D__$(ENDIANESS)__
 
 COMMON_CFLAGS = $(INCLUDES_FLAGS) -O$(OPTIMIZATION) -imacros $(CONFIG_HEADER) \