diff --git a/translator/deepl-translate/src/main/kotlin/DeeplClient.kt b/translator/deepl-translate/src/main/kotlin/DeeplClient.kt
index e1f9a7cac4..71d08922cf 100644
--- a/translator/deepl-translate/src/main/kotlin/DeeplClient.kt
+++ b/translator/deepl-translate/src/main/kotlin/DeeplClient.kt
@@ -99,7 +99,7 @@ class OkHttpDeeplClient(
             .build()
 
         glossaryId?.let {
-            formBuilder.add("glossaryId", it)
+            formBuilder.add("glossary_id", it)
         }
 
         val request = Request.Builder()