diff --git a/build/Android.common.mk b/build/Android.common.mk
index a0d8392..fd9dba5 100644
--- a/build/Android.common.mk
+++ b/build/Android.common.mk
@@ -180,6 +180,7 @@
 LIBART_TARGET_SRC_FILES := \
 	$(LIBART_COMMON_SRC_FILES) \
 	src/logging_android.cc \
+	src/monitor_android.cc \
 	src/runtime_android.cc \
 	src/thread_android.cc \
 	src/thread_arm.cc
@@ -187,6 +188,7 @@
 LIBART_HOST_SRC_FILES := \
 	$(LIBART_COMMON_SRC_FILES) \
 	src/logging_linux.cc \
+	src/monitor_linux.cc \
 	src/runtime_linux.cc \
 	src/thread_linux.cc \
 	src/thread_x86.cc