diff --git a/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SessionPool.java b/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SessionPool.java
index 3f21e28bd8ac..80e4d67eb664 100644
--- a/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SessionPool.java
+++ b/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SessionPool.java
@@ -599,7 +599,7 @@ private void closeIdleSessions(Instant currTime) {
         }
       }
       for (PooledSession sess : sessionsToClose) {
-        logger.log(Level.FINE, "Closing session %s", sess.getName());
+        logger.log(Level.FINE, "Closing session {0}", sess.getName());
         closeSession(sess);
       }
     }