diff --git a/configs/sim/README.txt b/configs/sim/README.txt
index 8e8fe42f127..aed86deff10 100644
--- a/configs/sim/README.txt
+++ b/configs/sim/README.txt
@@ -50,6 +50,11 @@ nx
   - The default in defconfig is to use a generic memory buffer
     for the framebuffer.  defconfig-x11 is an example with X11
     support enabled.
+  - The default is the single-user NX implementation.  To select
+    the multi-user NX implementation:
+
+      CONFG_NX_MULTIUSER=y
+      CONFIG_DISABLE_MQUEUE=n
 
 ostest
 
diff --git a/configs/sim/nx/defconfig b/configs/sim/nx/defconfig
index 1eaa2ca54a9..33e7732bbd9 100644
--- a/configs/sim/nx/defconfig
+++ b/configs/sim/nx/defconfig
@@ -124,7 +124,7 @@ CONFIG_DEV_LOWCONSOLE=n
 CONFIG_DISABLE_CLOCK=n
 CONFIG_DISABLE_POSIX_TIMERS=y
 CONFIG_DISABLE_PTHREAD=y
-CONFIG_DISABLE_SIGNALS=y
+CONFIG_DISABLE_SIGNALS=n
 CONFIG_DISABLE_MQUEUE=y
 CONFIG_DISABLE_MOUNTPOINT=y
 CONFIG_DISABLE_ENVIRON=y
diff --git a/configs/sim/nx/defconfig-x11 b/configs/sim/nx/defconfig-x11
index 58ae6a81d67..be2feabbc6d 100644
--- a/configs/sim/nx/defconfig-x11
+++ b/configs/sim/nx/defconfig-x11
@@ -124,7 +124,7 @@ CONFIG_DEV_LOWCONSOLE=n
 CONFIG_DISABLE_CLOCK=n
 CONFIG_DISABLE_POSIX_TIMERS=y
 CONFIG_DISABLE_PTHREAD=y
-CONFIG_DISABLE_SIGNALS=y
+CONFIG_DISABLE_SIGNALS=n
 CONFIG_DISABLE_MQUEUE=y
 CONFIG_DISABLE_MOUNTPOINT=y
 CONFIG_DISABLE_ENVIRON=y