diff --git a/lib/libc/gen/Makefile.inc b/lib/libc/gen/Makefile.inc
index 9eeab36f7d00..ae5a12d8b668 100644
--- a/lib/libc/gen/Makefile.inc
+++ b/lib/libc/gen/Makefile.inc
@@ -9,7 +9,6 @@ CONFSPACKAGE=   runtime
 SRCS+=	__getosreldate.c \
 	__pthread_mutex_init_calloc_cb_stub.c \
 	__xuname.c \
-	_once_stub.c \
 	_pthread_stubs.c \
 	_rand48.c \
 	_spinlock_stub.c \
diff --git a/lib/libsys/Makefile.sys b/lib/libsys/Makefile.sys
index e31a30d731bb..ef800e4d2445 100644
--- a/lib/libsys/Makefile.sys
+++ b/lib/libsys/Makefile.sys
@@ -32,6 +32,7 @@ PSEUDO+= _clock_gettime.o _gettimeofday.o
 # Sources common to both syscall interfaces:
 SRCS+=	\
 	__error.c \
+	_once_stub.c \
 	interposing_table.c
 
 SRCS+= getdents.c lstat.c mknod.c stat.c
diff --git a/lib/libc/gen/_once_stub.c b/lib/libsys/_once_stub.c
similarity index 100%
rename from lib/libc/gen/_once_stub.c
rename to lib/libsys/_once_stub.c