diff --git a/org.ntlab.traceAnalyzer/src/org/ntlab/deltaExtractor/Alias.java b/org.ntlab.traceAnalyzer/src/org/ntlab/deltaExtractor/Alias.java
index dac8427..5477266 100644
--- a/org.ntlab.traceAnalyzer/src/org/ntlab/deltaExtractor/Alias.java
+++ b/org.ntlab.traceAnalyzer/src/org/ntlab/deltaExtractor/Alias.java
@@ -65,8 +65,12 @@
 	}
 	
 	public int getLineNo() {
-		Statement statement = occurrencePoint.getStatement();
-		return statement.getLineNo();
+		try {
+			Statement statement = occurrencePoint.getStatement();
+			return statement.getLineNo();
+		} catch (Exception e) {
+			return -1;
+		}
 	}
 	
 }
\ No newline at end of file