diff --git a/libc/bionic/sys_msg.cpp b/libc/bionic/sys_msg.cpp
index 462c83b..4880356 100644
--- a/libc/bionic/sys_msg.cpp
+++ b/libc/bionic/sys_msg.cpp
@@ -32,8 +32,9 @@
 #include <unistd.h>
 
 int msgctl(int id, int cmd, msqid_ds* buf) {
-#if !defined(__LP64__)
+#if !defined(__LP64__) || defined(__mips__)
   // Annoyingly, the kernel requires this for 32-bit but rejects it for 64-bit.
+  // Mips64 is an exception to this, it requires the flag.
   cmd |= IPC_64;
 #endif
 #if defined(SYS_msgctl)