diff --git a/org.eclipse.ui.console/src/org/eclipse/ui/internal/console/IOConsolePartition.java b/org.eclipse.ui.console/src/org/eclipse/ui/internal/console/IOConsolePartition.java
index f9675bf..6c0d07c 100644
--- a/org.eclipse.ui.console/src/org/eclipse/ui/internal/console/IOConsolePartition.java
+++ b/org.eclipse.ui.console/src/org/eclipse/ui/internal/console/IOConsolePartition.java
@@ -75,6 +75,11 @@
 	 * @param offset the offset in the partition
 	 */
 	public void insert(String s, int insertOffset) {
+		if (insertOffset < 0) {
+			insertOffset = 0;
+		} else if (insertOffset > buffer.length()) {
+			insertOffset = buffer.length();
+		}
 		buffer.insert(insertOffset, s);
 		length += s.length();
 	}