diff --git a/lib/plugins/environments.js b/lib/plugins/environments.js
index 52a29612..5062503f 100644
--- a/lib/plugins/environments.js
+++ b/lib/plugins/environments.js
@@ -10,11 +10,7 @@ module.exports = class Environments extends Diffable {
       // Force all names to lowercase to avoid comparison issues.
       this.entries.forEach((environment) => {
         environment.name = environment.name.toLowerCase()
-        if (environment.variables) {
-          environment.variables.forEach((variable) => {
-            variable.name = variable.name.toLowerCase()
-          })
-        }
+        // Do not force variables to lowercase as they are case-sensitive on create (POST).
       })
     }
   }
@@ -297,11 +293,11 @@ module.exports = class Environments extends Diffable {
 
       for (const variable of attrs.variables) {
         const existingVariable = existingVariables.find(
-          (_var) => _var.name === variable.name
+          (_var) => _var.name === variable.name.toLowerCase()
         )
         if (existingVariable) {
           existingVariables = existingVariables.filter(
-            (_var) => _var.name === variable.name
+            (_var) => _var.name !== variable.name.toLowerCase()
           )
           if (existingVariable.value !== variable.value) {
             await this.github.request(