diff --git a/core-java-modules/core-java-io-conversions-2/src/main/java/com/baeldung/csv/WriteCsvFileExample.java b/core-java-modules/core-java-io-conversions-2/src/main/java/com/baeldung/csv/WriteCsvFileExample.java
index f409d05b06..184ae6d3e3 100644
--- a/core-java-modules/core-java-io-conversions-2/src/main/java/com/baeldung/csv/WriteCsvFileExample.java
+++ b/core-java-modules/core-java-io-conversions-2/src/main/java/com/baeldung/csv/WriteCsvFileExample.java
@@ -12,6 +12,10 @@ public class WriteCsvFileExample {
     }
 
     public String escapeSpecialCharacters(String data) {
+        if (data == null) {
+            throw new IllegalArgumentException("Input data cannot be null");
+        }
+        
         String escapedData = data.replaceAll("\\R", " ");
         if (data.contains(",") || data.contains("\"") || data.contains("'")) {
             data = data.replace("\"", "\"\"");