diff --git a/src/main/java/Selenium2Library.java b/src/main/java/Selenium2Library.java
index ef9c351..6970a6d 100644
--- a/src/main/java/Selenium2Library.java
+++ b/src/main/java/Selenium2Library.java
@@ -526,7 +526,7 @@ public static Selenium2Library getLibraryInstance() throws ScriptException {
 	protected Object[] toStrings(Object[] args) {
 		Object[] newArgs = new Object[args.length];
 		for (int i = 0; i < newArgs.length; i++) {
-			if (args[i].getClass().isArray()) {
+			if (args[i] == null || args[i].getClass().isArray()) {
 				newArgs[i] = args[i];
 			} else {
 				newArgs[i] = args[i].toString();
@@ -534,4 +534,4 @@ protected Object[] toStrings(Object[] args) {
 		}
 		return newArgs;
 	}
-}
\ No newline at end of file
+}