diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index d15f671c..64c6c975 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -87,7 +87,7 @@ flatpak:
   variables:
     APP_ID: org.gnome.Geary.Devel
     FLATPAK_MODULE: geary
-    MANIFEST_PATH: org.gnome.Geary.yml
+    MANIFEST_PATH: org.gnome.Geary.yaml
     MESON_ARGS: "-Dprofile=development"
     RUNTIME_REPO: 'https://nightly.gnome.org/gnome-nightly.flatpakrepo'
     TEST_RUN_ARGS: $TEST_ARGS
diff --git a/meson.build b/meson.build
index 0bdd1568..c21b4623 100644
--- a/meson.build
+++ b/meson.build
@@ -171,7 +171,7 @@ custom_target(
   'org.gnome.Geary.json',
   build_by_default: true,
   command: [yaml_to_json, '@INPUT@', meson.source_root(), '@OUTPUT@'],
-  input: files('org.gnome.Geary.yml'),
+  input: files('org.gnome.Geary.yaml'),
   output: 'org.gnome.Geary.json'
 )
 
diff --git a/org.gnome.Geary.json b/org.gnome.Geary.json
index ffa0c039..8a81169d 100644
--- a/org.gnome.Geary.json
+++ b/org.gnome.Geary.json
@@ -1,4 +1,4 @@
-/* Automatically generated from org.gnome.Geary.yml, do not modify. */
+/* Automatically generated from org.gnome.Geary.yaml, do not modify. */
 {
     "app-id": "org.gnome.Geary.Devel",
     "branch": "master",
diff --git a/org.gnome.Geary.yml b/org.gnome.Geary.yaml
similarity index 100%
rename from org.gnome.Geary.yml
rename to org.gnome.Geary.yaml