diff --git a/Troubleshooting.md b/Troubleshooting.md
index 29bae27..0d226cd 100644
--- a/Troubleshooting.md
+++ b/Troubleshooting.md
@@ -1,3 +1,11 @@
+## Wrong file opener
+
+Use the following command to set default openers for mimetypes:
+
+    xdg-mime default application mimetype(s)
+    e.g.
+    xdg-mime default sxiv.desktop image/jpeg image/png
+
 ## Batch rename limits
 
 **TL;DR:** If you need a full-featured batch-renamer, install plugins. `nnn` auto-detects and invokes the internal plugin `.nmv` (a bash script) which is feature-complete.