diff --git a/Sources/_OpenAPIGeneratorCore/Diagnostics.swift b/Sources/_OpenAPIGeneratorCore/Diagnostics.swift
index f85c991d..08b561a0 100644
--- a/Sources/_OpenAPIGeneratorCore/Diagnostics.swift
+++ b/Sources/_OpenAPIGeneratorCore/Diagnostics.swift
@@ -322,7 +322,7 @@ public struct StdErrPrintingDiagnosticCollector: DiagnosticCollector, Sendable {
     /// Emits a diagnostic message to standard error.
     ///
     /// - Parameter diagnostic: The diagnostic message to emit.
-    public func emit(_ diagnostic: Diagnostic) { stdErrHandle.write(diagnostic.description) }
+    public func emit(_ diagnostic: Diagnostic) { stdErrHandle.write(diagnostic.description + "\n") }
 }
 
 /// A no-op collector, silently ignores all diagnostics.