diff --git a/linux-user/strace.c b/linux-user/strace.c
index 5027289bdd..081fc87344 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -1360,7 +1360,8 @@ UNUSED static const struct flags termios_lflags[] = {
     FLAG_END,
 };
 
-UNUSED static const struct flags mlockall_flags[] = {
+#ifdef TARGET_NR_mlockall
+static const struct flags mlockall_flags[] = {
     FLAG_TARGET(MCL_CURRENT),
     FLAG_TARGET(MCL_FUTURE),
 #ifdef MCL_ONFAULT
@@ -1368,6 +1369,7 @@ UNUSED static const struct flags mlockall_flags[] = {
 #endif
     FLAG_END,
 };
+#endif
 
 /* IDs of the various system clocks */
 #define TARGET_CLOCK_REALTIME              0