diff --git a/models/data-types/vehicle-type-counts.yaml b/models/data-types/vehicle-type-counts.yaml
index 6827e10..026c787 100644
--- a/models/data-types/vehicle-type-counts.yaml
+++ b/models/data-types/vehicle-type-counts.yaml
@@ -11,5 +11,5 @@ propertyNames:
   $ref: ./vehicle-type.yaml
 
 patternProperties:
-  "": # i.e. match all properties
+  ".": # i.e. match all properties
     $ref: ./integer-positive.yaml
diff --git a/models/policy-rule.yaml b/models/policy-rule.yaml
index 0b32feb..1d44399 100644
--- a/models/policy-rule.yaml
+++ b/models/policy-rule.yaml
@@ -21,7 +21,7 @@ $defs:
       # allow any vehicle state to be a property name
       $ref: ./data-types/vehicle-state.yaml
     patternProperties:
-      "": # i.e. match all properties of the `states` object
+      ".": # i.e. match all properties of the `states` object
         type: array
         uniqueItems: true
         items: