diff --git a/kernel/Makefile b/kernel/Makefile
index 752bd7d..21df9a3 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -16,6 +16,7 @@
 ifeq ($(CONFIG_COMPAT),y)
 obj-$(CONFIG_FUTEX) += futex_compat.o
 endif
+obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
 obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
 obj-$(CONFIG_SMP) += cpu.o spinlock.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o