diff --git a/debian/changelog b/debian/changelog
index f5c21d2..196a3ee 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -2,6 +2,7 @@
 
   * Trim trailing whitespace.
   * Use secure copyright file specification URI.
+  * Upgrade to newer source format 3.0 (quilt).
 
  -- Debian Janitor <janitor@jelmer.uk>  Thu, 27 May 2021 00:01:14 -0000
 
diff --git a/debian/source/format b/debian/source/format
index d3827e7..163aaf8 100644
--- a/debian/source/format
+++ b/debian/source/format
@@ -1 +1 @@
-1.0
+3.0 (quilt)