diff --git a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
index d6a46178257..eb64bf1cd79 100644
--- a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
+++ b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
@@ -1443,7 +1443,9 @@ public String toString() {
     sb.append(", partSize=").append(partSize);
     sb.append(", enableMultiObjectsDelete=").append(enableMultiObjectsDelete);
     sb.append(", maxKeys=").append(maxKeys);
-    sb.append(", cannedACL=").append(cannedACL.toString());
+    if (cannedACL != null) {
+      sb.append(", cannedACL=").append(cannedACL.toString());
+    }
     sb.append(", readAhead=").append(readAhead);
     sb.append(", blockSize=").append(getDefaultBlockSize());
     sb.append(", multiPartThreshold=").append(multiPartThreshold);