diff --git a/modules/installer/tools/nixos-rebuild.sh b/modules/installer/tools/nixos-rebuild.sh
index c2210b629394..6fc9014027d9 100644
--- a/modules/installer/tools/nixos-rebuild.sh
+++ b/modules/installer/tools/nixos-rebuild.sh
@@ -188,6 +188,9 @@ fi
 # If we're not just building, then make the new configuration the boot
 # default and/or activate it now.
 if test "$action" = switch -o "$action" = boot -o "$action" = test; then
+    # Just in case the new configuration hangs the system, do a sync now.
+    sync
+    
     $pathToConfig/bin/switch-to-configuration "$action"
 fi