diff --git a/changelog/unreleased/change-replace-deprecated-substr b/changelog/unreleased/change-replace-deprecated-substr
new file mode 100644
index 0000000000..5333cf52dc
--- /dev/null
+++ b/changelog/unreleased/change-replace-deprecated-substr
@@ -0,0 +1,7 @@
+Change: Replace deprecated String.prototype.substr()
+
+We've replaced all occurrences of the deprecated String.prototype.substr()
+function with String.prototype.slice() which works similarly but isn't
+deprecated.
+
+https://github.com/owncloud/ocis/pull/3448