diff --git a/conf/example.conf.in b/conf/example.conf.in
index 923d238..a069dac 100644
--- a/conf/example.conf.in
+++ b/conf/example.conf.in
@@ -1778,7 +1778,7 @@ activation {
 	# Prior to version 2.02.62, LVM used mlockall() to pin the whole
 	# process's memory while activating devices.
 	# This configuration option has an automatic default value.
-	# use_mlockall = 0
+	# use_mlockall = 1
 
 	# Configuration option activation/monitoring.
 	# Monitor LVs that are activated.
diff --git a/lib/config/defaults.h b/lib/config/defaults.h
index 571054d..1ff3637 100644
--- a/lib/config/defaults.h
+++ b/lib/config/defaults.h
@@ -66,7 +66,7 @@
 #define DEFAULT_LVMLOCKD_LOCK_RETRIES 3
 #define DEFAULT_LVMETAD_UPDATE_WAIT_TIME 10
 #define DEFAULT_PRIORITISE_WRITE_LOCKS 1
-#define DEFAULT_USE_MLOCKALL 0
+#define DEFAULT_USE_MLOCKALL 1
 #define DEFAULT_METADATA_READ_ONLY 0
 #define DEFAULT_LVDISPLAY_SHOWS_FULL_DEVICE_PATH 0
 #define DEFAULT_UNKNOWN_DEVICE_NAME "[unknown]"