diff --git a/index.js b/index.js
index c68df12..3f94a7b 100644
--- a/index.js
+++ b/index.js
@@ -4,7 +4,6 @@
 // Created by Curran Kelleher and Chrostophe Serafin.
 // Contributions from Paul Brewer and Javier Blanco Martinez.
 const objectPath = require('object-path');
-const dedupe = require('dedupe');
 
 // An enhanced version of `typeof` that handles arrays and dates as well.
 function type(value) {
@@ -42,11 +41,7 @@ function Parameter(match) {
 
 // Constructs a template function with deduped `parameters` property.
 function Template(fn, parameters) {
-  // Paul Brewer Dec 2017 add deduplication call, use only key property to eliminate
-  Object.assign(fn, {
-    parameters: dedupe(parameters, item => item.key)
-  });
-
+  fn.parameters = Array.from(new Map(parameters.map(parameter => [parameter.key, parameter])).values())
   return fn;
 }
 
diff --git a/package.json b/package.json
index 9933153..dcd8dcd 100644
--- a/package.json
+++ b/package.json
@@ -25,12 +25,11 @@
   },
   "homepage": "https://github.com/datavis-tech/json-templates#readme",
   "devDependencies": {
-    "mocha": "^9.1.2",
-    "rollup": "^2.58.0",
+    "mocha": "^10.2.0",
+    "rollup": "^3.26.0",
     "rollup-plugin-buble": "^0.19.8"
   },
   "dependencies": {
-    "dedupe": "^3.0.2",
     "object-path": "^0.11.8"
   }
 }