diff --git a/src/main/java/org/fusesource/jansi/io/AnsiProcessor.java b/src/main/java/org/fusesource/jansi/io/AnsiProcessor.java
index d4b825cf..ff3c12f5 100644
--- a/src/main/java/org/fusesource/jansi/io/AnsiProcessor.java
+++ b/src/main/java/org/fusesource/jansi/io/AnsiProcessor.java
@@ -252,6 +252,7 @@ private int optionInt(ArrayList<Object> options, int index, int defaultValue) {
             if (value == null) {
                 return defaultValue;
             }
+            if (!value.getClass().equals(Integer.class)) throw new IllegalArgumentException();
             return (Integer) value;
         }
         return defaultValue;