diff --git a/main/src/main/scala/sbt/internal/server/BuildServerReporter.scala b/main/src/main/scala/sbt/internal/server/BuildServerReporter.scala
index 98d59d645..3c8c8bb0c 100644
--- a/main/src/main/scala/sbt/internal/server/BuildServerReporter.scala
+++ b/main/src/main/scala/sbt/internal/server/BuildServerReporter.scala
@@ -174,7 +174,7 @@ final class BuildServerReporterImpl(
       Diagnostic(
         range,
         Option(toDiagnosticSeverity(problem.severity)),
-        None,
+        problem.diagnosticCode().toOption.map(_.code),
         Option("sbt"),
         problem.message
       )