diff --git a/languages.toml b/languages.toml
index 426778b4cb721..4db04e3a1ca77 100644
--- a/languages.toml
+++ b/languages.toml
@@ -1183,6 +1183,7 @@ file-types = ["java", "jav", "pde"]
 roots = ["pom.xml", "build.gradle", "build.gradle.kts"]
 language-servers = [ "jdtls" ]
 indent = { tab-width = 2, unit = "  " }
+comment-token = "//"
 
 [[grammar]]
 name = "java"