diff --git a/bindings/node/index.js b/bindings/node/index.js
index 419f5c4..a6030cf 100644
--- a/bindings/node/index.js
+++ b/bindings/node/index.js
@@ -41,8 +41,8 @@ async function transformer (root, path, ruleset, trails, originalSchema, from) {
         omit: (object, keys) => {
           return _.omit(object, _.castArray(keys))
         },
-        replace: (value, string, replacement) => {
-          return value.replaceAll(string, replacement)
+        replace: (value, regex, replacement) => {
+          return value.replace(new RegExp(regex, 'g'), replacement)
         }
       })
 
diff --git a/rules/jsonschema-2019-09-to-2020-12.json b/rules/jsonschema-2019-09-to-2020-12.json
index 8fac8e1..bdaeb79 100644
--- a/rules/jsonschema-2019-09-to-2020-12.json
+++ b/rules/jsonschema-2019-09-to-2020-12.json
@@ -47,6 +47,32 @@
         ]
       }
     },
+    {
+      "vocabulary": "https://json-schema.org/draft/2019-09/vocab/validation",
+      "condition": {
+        "$schema": "https://json-schema.org/draft/2020-12/schema",
+        "$id": "https://github.com/sourcemeta/alterschema/rules/jsonschema-2019-09-to-2020-12/open-tuple-in-ref",
+        "$comment": "https://json-schema.org/draft/2020-12/release-notes.html",
+        "type": "object",
+        "required": [ "$ref" ],
+        "properties": {
+          "$ref": {
+            "type": "string",
+            "pattern": "/items/\\d+"
+          }
+        }
+      },
+      "transform": {
+        "$merge": [
+          { "$eval": "omit(schema, '$ref')" },
+          {
+            "$$ref": {
+              "$eval": "replace(schema['$ref'], '/items/(\\d+)', '/prefixItems/$1')"
+            }
+          }
+        ]
+      }
+    },
     {
       "vocabulary": "https://json-schema.org/draft/2019-09/vocab/validation",
       "condition": {
diff --git a/rules/jsonschema-draft7-to-2019-09.json b/rules/jsonschema-draft7-to-2019-09.json
index abe60c8..6a0621f 100644
--- a/rules/jsonschema-draft7-to-2019-09.json
+++ b/rules/jsonschema-draft7-to-2019-09.json
@@ -89,7 +89,7 @@
           { "$eval": "omit(schema, '$ref')" },
           {
             "$$ref": {
-              "$eval": "replace(schema['$ref'], 'definitions', '$defs')"
+              "$eval": "replace(schema['$ref'], '/definitions/', '/$defs/')"
             }
           }
         ]
diff --git a/test/rules/jsonschema-2019-09-to-2020-12.json b/test/rules/jsonschema-2019-09-to-2020-12.json
index cfeb13c..c1d774f 100644
--- a/test/rules/jsonschema-2019-09-to-2020-12.json
+++ b/test/rules/jsonschema-2019-09-to-2020-12.json
@@ -167,5 +167,39 @@
         "foo": { "$dynamicRef": "#" }
       }
     }
+  },
+  {
+    "name": "items to prefixItems within $ref",
+    "schema": {
+      "$schema": "https://json-schema.org/draft/2019-09/schema",
+      "items": [
+        { "type": "integer" },
+        { "$ref": "#/items/0" }
+      ]
+    },
+    "expected": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema",
+      "prefixItems": [
+        { "type": "integer" },
+        { "$ref": "#/prefixItems/0" }
+      ]
+    }
+  },
+  {
+    "name": "items not to prefixItems within $ref",
+    "schema": {
+      "$schema": "https://json-schema.org/draft/2019-09/schema",
+      "items": { "type": "integer" },
+      "properties": {
+        "foo": { "$ref": "#/items" }
+      }
+    },
+    "expected": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema",
+      "items": { "type": "integer" },
+      "properties": {
+        "foo": { "$ref": "#/items" }
+      }
+    }
   }
 ]
diff --git a/test/rules/jsonschema-draft4-to-2020-12.json b/test/rules/jsonschema-draft4-to-2020-12.json
index 2494b0c..a2af82a 100644
--- a/test/rules/jsonschema-draft4-to-2020-12.json
+++ b/test/rules/jsonschema-draft4-to-2020-12.json
@@ -225,5 +225,22 @@
         { "$ref": "#/prefixItems/0" }
       ]
     }
+  },
+  {
+    "name": "items not to prefixItems within $ref",
+    "schema": {
+      "$schema": "http://json-schema.org/draft-04/schema#",
+      "items": { "type": "integer" },
+      "properties": {
+        "foo": { "$ref": "#/items" }
+      }
+    },
+    "expected": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema",
+      "items": { "type": "integer" },
+      "properties": {
+        "foo": { "$ref": "#/items" }
+      }
+    }
   }
 ]
diff --git a/test/rules/jsonschema-draft6-to-2020-12.json b/test/rules/jsonschema-draft6-to-2020-12.json
index 98bb24c..6226beb 100644
--- a/test/rules/jsonschema-draft6-to-2020-12.json
+++ b/test/rules/jsonschema-draft6-to-2020-12.json
@@ -149,5 +149,39 @@
         "foo": false
       }
     }
+  },
+  {
+    "name": "items to prefixItems within $ref",
+    "schema": {
+      "$schema": "http://json-schema.org/draft-06/schema#",
+      "items": [
+        { "type": "integer" },
+        { "$ref": "#/items/0" }
+      ]
+    },
+    "expected": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema",
+      "prefixItems": [
+        { "type": "integer" },
+        { "$ref": "#/prefixItems/0" }
+      ]
+    }
+  },
+  {
+    "name": "items not to prefixItems within $ref",
+    "schema": {
+      "$schema": "http://json-schema.org/draft-06/schema#",
+      "items": { "type": "integer" },
+      "properties": {
+        "foo": { "$ref": "#/items" }
+      }
+    },
+    "expected": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema",
+      "items": { "type": "integer" },
+      "properties": {
+        "foo": { "$ref": "#/items" }
+      }
+    }
   }
 ]
diff --git a/test/rules/jsonschema-draft7-to-2020-12.json b/test/rules/jsonschema-draft7-to-2020-12.json
index 8f92e9b..85e6206 100644
--- a/test/rules/jsonschema-draft7-to-2020-12.json
+++ b/test/rules/jsonschema-draft7-to-2020-12.json
@@ -183,5 +183,39 @@
         }
       }
     }
+  },
+  {
+    "name": "items to prefixItems within $ref",
+    "schema": {
+      "$schema": "http://json-schema.org/draft-07/schema#",
+      "items": [
+        { "type": "integer" },
+        { "$ref": "#/items/0" }
+      ]
+    },
+    "expected": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema",
+      "prefixItems": [
+        { "type": "integer" },
+        { "$ref": "#/prefixItems/0" }
+      ]
+    }
+  },
+  {
+    "name": "items not to prefixItems within $ref",
+    "schema": {
+      "$schema": "http://json-schema.org/draft-07/schema#",
+      "items": { "type": "integer" },
+      "properties": {
+        "foo": { "$ref": "#/items" }
+      }
+    },
+    "expected": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema",
+      "items": { "type": "integer" },
+      "properties": {
+        "foo": { "$ref": "#/items" }
+      }
+    }
   }
 ]