diff --git a/spring-core/src/main/java/org/springframework/core/io/buffer/DefaultDataBuffer.java b/spring-core/src/main/java/org/springframework/core/io/buffer/DefaultDataBuffer.java
index 2efc753ab6..f4c898a8ee 100644
--- a/spring-core/src/main/java/org/springframework/core/io/buffer/DefaultDataBuffer.java
+++ b/spring-core/src/main/java/org/springframework/core/io/buffer/DefaultDataBuffer.java
@@ -453,9 +453,9 @@ public class DefaultDataBuffer implements DataBuffer {
 
 	private void checkIndex(int index, int length) {
 		assertIndex(index >= 0, "index %d must be >= 0", index);
-		assertIndex(length >= 0, "length %d must be >= 0", index);
+		assertIndex(length >= 0, "length %d must be >= 0", length);
 		assertIndex(index <= this.capacity, "index %d must be <= %d", index, this.capacity);
-		assertIndex(length <= this.capacity, "length %d must be <= %d", index, this.capacity);
+		assertIndex(length <= this.capacity, "length %d must be <= %d", length, this.capacity);
 	}
 
 	private void assertIndex(boolean expression, String format, Object... args) {