diff --git a/src/java/net/rkoubou/kspparser/KSPSyntaxParser.java b/src/java/net/rkoubou/kspparser/KSPSyntaxParser.java
index 8623a5a..3c7b32f 100644
--- a/src/java/net/rkoubou/kspparser/KSPSyntaxParser.java
+++ b/src/java/net/rkoubou/kspparser/KSPSyntaxParser.java
@@ -64,6 +64,7 @@ static public void main( String[] args ) throws Throwable
             ASTRootNode rootNode = p.analyzeSyntax();
             if( rootNode == null || AnalyzeErrorCounter.hasError() )
             {
+                System.exit( 1 );
                 return;
             }