1 files changed, 1 insertions, 1 deletions
diff --git a/luni/src/main/java/java/io/BufferedReader.java b/luni/src/main/java/java/io/BufferedReader.java
index 03ecf9f..95a23e9 100644
--- a/luni/src/main/java/java/io/BufferedReader.java
+++ b/luni/src/main/java/java/io/BufferedReader.java
@@ -190,7 +190,7 @@ public class BufferedReader extends Reader {
     @Override
     public void mark(int markLimit) throws IOException {
         if (markLimit < 0) {
-            throw new IllegalArgumentException();
+            throw new IllegalArgumentException("markLimit < 0:" + markLimit);
         }
         synchronized (lock) {
             checkNotClosed();