diff --git a/src/output.h b/src/output.h
--- a/src/output.h
+++ b/src/output.h
@@ -181,6 +181,13 @@
         void setClones(QList<int> outputlist);
 
         void setEdid(const QByteArray &rawData);
+
+        /**
+         * edid returns the output's EDID information if available.
+         *
+         * The output maintains ownership of the returned Edid, so the caller should not delete it.
+         * Note that the edid is only valid as long as the output is alive.
+         */
         Edid* edid() const;
 
         /**
diff --git a/src/output.cpp b/src/output.cpp
--- a/src/output.cpp
+++ b/src/output.cpp
@@ -93,7 +93,7 @@
     bool primary;
     bool followPreferredMode = false;
 
-    mutable QScopedPointer<Edid> edid;
+    QScopedPointer<Edid> edid;
 };
 
 bool Output::Private::compareModeList(const ModeList& before, const ModeList &after)