diff --git a/bsd-user/bsd-mem.h b/bsd-user/bsd-mem.h
index 0f9e4a1d4b..5e885823a7 100644
--- a/bsd-user/bsd-mem.h
+++ b/bsd-user/bsd-mem.h
@@ -88,4 +88,15 @@ static inline abi_long do_bsd_mprotect(abi_long arg1, abi_long arg2,
     return get_errno(target_mprotect(arg1, arg2, arg3));
 }
 
+/* msync(2) */
+static inline abi_long do_bsd_msync(abi_long addr, abi_long len, abi_long flags)
+{
+    if (!guest_range_valid_untagged(addr, len)) {
+        /* It seems odd, but POSIX wants this to be ENOMEM */
+        return -TARGET_ENOMEM;
+    }
+
+    return get_errno(msync(g2h_untagged(addr), len, flags));
+}
+
 #endif /* BSD_USER_BSD_MEM_H */
diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c
index 2d8f1a953b..2525e0bc31 100644
--- a/bsd-user/freebsd/os-syscall.c
+++ b/bsd-user/freebsd/os-syscall.c
@@ -811,6 +811,10 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
         ret = do_bsd_mprotect(arg1, arg2, arg3);
         break;
 
+    case TARGET_FREEBSD_NR_msync: /* msync(2) */
+        ret = do_bsd_msync(arg1, arg2, arg3);
+        break;
+
 #if defined(__FreeBSD_version) && __FreeBSD_version >= 1300048
     case TARGET_FREEBSD_NR_shm_open2: /* shm_open2(2) */
         ret = do_freebsd_shm_open2(arg1, arg2, arg3, arg4, arg5);