diff --git a/libc/Android.mk b/libc/Android.mk
index f09733e..d6274dd 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -131,6 +131,7 @@
     bionic/ffs.cpp \
     bionic/flockfile.cpp \
     bionic/fpclassify.cpp \
+    bionic/ftruncate.cpp \
     bionic/futimens.cpp \
     bionic/getcwd.cpp \
     bionic/gethostname.cpp \