diff --git a/src/appearancegtk2.cpp b/src/appearancegtk2.cpp
--- a/src/appearancegtk2.cpp
+++ b/src/appearancegtk2.cpp
@@ -87,7 +87,7 @@
 {
     QFile gtkrc{gtkrcFile};
 
-    if (gtkrc.open(QIODevice::ReadOnly | QIODevice::Text)) {
+    if (gtkrc.open(QIODevice::ReadWrite | QIODevice::Text)) {
         QString fileContents{gtkrc.readAll()};
 
         modifyGtkrcContents(fileContents);