diff --git a/operations/mimir-tests/build.sh b/operations/mimir-tests/build.sh
index 25f0296e40f..0aa0916335d 100755
--- a/operations/mimir-tests/build.sh
+++ b/operations/mimir-tests/build.sh
@@ -8,7 +8,7 @@ rm -rf jsonnet-tests && mkdir jsonnet-tests
 cd jsonnet-tests
 
 # Initialise the Tanka.
-tk init --k8s=1.18
+tk init --k8s=1.21
 
 # Install Mimir jsonnet from this branch.
 jb install ../operations/mimir
diff --git a/operations/mimir/README.md b/operations/mimir/README.md
index ff29bbecbbc..4a5faf61176 100644
--- a/operations/mimir/README.md
+++ b/operations/mimir/README.md
@@ -28,7 +28,7 @@ set -e
 
 # Initialise the Tanka.
 mkdir jsonnet-example && cd jsonnet-example
-tk init --k8s=1.18
+tk init --k8s=1.21
 
 # Install Mimir jsonnet.
 jb install github.com/grafana/mimir/operations/mimir@main
diff --git a/operations/mimir/getting-started.sh b/operations/mimir/getting-started.sh
index b5c31dfe517..6885142687d 100755
--- a/operations/mimir/getting-started.sh
+++ b/operations/mimir/getting-started.sh
@@ -5,7 +5,7 @@ set -e
 
 # Initialise the Tanka.
 mkdir jsonnet-example && cd jsonnet-example
-tk init --k8s=1.18
+tk init --k8s=1.21
 
 # Install Mimir jsonnet.
 jb install github.com/grafana/mimir/operations/mimir@main