diff --git a/libc/Android.mk b/libc/Android.mk
index ee09087..b77e394 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -222,6 +222,7 @@
     bionic/__errno.cpp \
     bionic/eventfd_read.cpp \
     bionic/eventfd_write.cpp \
+    bionic/ffs.cpp \
     bionic/fork.cpp \
     bionic/futimens.cpp \
     bionic/getauxval.cpp \