diff --git a/.github/workflows/build-toolchains.yml b/.github/workflows/build-toolchains.yml
index 85879f6f..166fceeb 100644
--- a/.github/workflows/build-toolchains.yml
+++ b/.github/workflows/build-toolchains.yml
@@ -1,3 +1,4 @@
+---
 name: Build toolchains
 
 on:
diff --git a/.github/workflows/continuous-integration-workflow.yml b/.github/workflows/continuous-integration-workflow.yml
index c5696f5f..ddebacc4 100644
--- a/.github/workflows/continuous-integration-workflow.yml
+++ b/.github/workflows/continuous-integration-workflow.yml
@@ -1,3 +1,4 @@
+---
 name: CI
 
 on:
diff --git a/.yamllint b/.yamllint
new file mode 100644
index 00000000..0cd24420
--- /dev/null
+++ b/.yamllint
@@ -0,0 +1,9 @@
+---
+yaml-files:
+  - '*.yaml'
+  - '*.yml'
+  - '.yamllint'
+
+rules:
+  truthy:
+    allowed-values: ['TRUE', 'True', 'true', 'FALSE', 'False', 'false', 'YES', 'Yes', 'yes', 'NO', 'No', 'no', 'ON', 'On', 'on', 'OFF', 'Off', 'off']