diff --git a/src/handleOptions.js b/src/handleOptions.js
index 192f6744..92f4c9b9 100644
--- a/src/handleOptions.js
+++ b/src/handleOptions.js
@@ -83,7 +83,7 @@ exports.handleExtends = () => {
  * @returns {{}|{tagFormat: String}}
  */
 exports.handleTagFormat = () => {
-  const tagFormat = core.getInput(inputs.tagFormat);
+  const tagFormat = core.getInput(inputs.tag_format);
 
   if (tagFormat) {
     return {
diff --git a/src/inputs.json b/src/inputs.json
index 758a7198..2b83ebef 100644
--- a/src/inputs.json
+++ b/src/inputs.json
@@ -6,5 +6,5 @@
   "dry_run": "dry_run",
   "extends": "extends",
   "working_directory": "working_directory",
-  "tagFormat": "tagFormat"
+  "tag_format": "tag_format"
 }