diff --git a/daint.cscs.ch/gpu/codes/QuantumESPRESSO.yml b/daint.cscs.ch/gpu/codes/QuantumESPRESSO.yml
index 663aa43..b6eb38b 100644
--- a/daint.cscs.ch/gpu/codes/QuantumESPRESSO.yml
+++ b/daint.cscs.ch/gpu/codes/QuantumESPRESSO.yml
@@ -21,7 +21,7 @@ metadata:
             type: list
             key_display: QE version
             options:
-                - "7.0"
-                - "7.1"
-                - "7.2"
-            default: "7.2"
+                - '7.0'
+                - '7.1'
+                - '7.2'
+            default: '7.2'
diff --git a/daint.cscs.ch/mc/codes/QuantumESPRESSO.yml b/daint.cscs.ch/mc/codes/QuantumESPRESSO.yml
index 1acf05c..027633a 100644
--- a/daint.cscs.ch/mc/codes/QuantumESPRESSO.yml
+++ b/daint.cscs.ch/mc/codes/QuantumESPRESSO.yml
@@ -21,6 +21,6 @@ metadata:
             type: list
             key_display: QE version
             options:
-                - "7.0"
-                - "7.1"
-            default: "7.1"
+                - '7.0'
+                - '7.1'
+            default: '7.1'