diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/MongoTransactionManager.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/MongoTransactionManager.java
index a86d771ab..70788153a 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/MongoTransactionManager.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/MongoTransactionManager.java
@@ -397,7 +397,7 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 				debugString += String.format("causallyConsistent = %s, ", session.isCausallyConsistent());
 				debugString += String.format("txActive = %s, ", session.hasActiveTransaction());
 				debugString += String.format("txNumber = %d, ", session.getServerSession().getTransactionNumber());
-				debugString += String.format("closed = %d, ", session.getServerSession().isClosed());
+				debugString += String.format("closed = %b, ", session.getServerSession().isClosed());
 				debugString += String.format("clusterTime = %s", session.getClusterTime());
 			} else {
 				debugString += "id = n/a";
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoTransactionManager.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoTransactionManager.java
index cb181d711..d2c83c73e 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoTransactionManager.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoTransactionManager.java
@@ -401,7 +401,7 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 				debugString += String.format("causallyConsistent = %s, ", session.isCausallyConsistent());
 				debugString += String.format("txActive = %s, ", session.hasActiveTransaction());
 				debugString += String.format("txNumber = %d, ", session.getServerSession().getTransactionNumber());
-				debugString += String.format("closed = %d, ", session.getServerSession().isClosed());
+				debugString += String.format("closed = %b, ", session.getServerSession().isClosed());
 				debugString += String.format("clusterTime = %s", session.getClusterTime());
 			} else {
 				debugString += "id = n/a";