diff --git a/libc/include/sys/shm.h b/libc/include/sys/shm.h
index 9d58046..fb6f20c 100644
--- a/libc/include/sys/shm.h
+++ b/libc/include/sys/shm.h
@@ -49,7 +49,7 @@
 /** Not useful on Android; disallowed by SELinux. */
 void* _Nonnull shmat(int __shm_id, const void* _Nullable __addr, int __flags) __INTRODUCED_IN(26);
 /** Not useful on Android; disallowed by SELinux. */
-int shmctl(int __shm_id, int __cmd, struct shmid_ds* _Nullable __buf) __INTRODUCED_IN(26);
+int shmctl(int __shm_id, int __op, struct shmid_ds* _Nullable __buf) __INTRODUCED_IN(26);
 /** Not useful on Android; disallowed by SELinux. */
 int shmdt(const void* _Nonnull __addr) __INTRODUCED_IN(26);
 /** Not useful on Android; disallowed by SELinux. */