diff --git a/powerauth-java-server/src/main/java/io/getlime/security/powerauth/app/server/service/behavior/tasks/OperationServiceBehavior.java b/powerauth-java-server/src/main/java/io/getlime/security/powerauth/app/server/service/behavior/tasks/OperationServiceBehavior.java
index 2ac63646d..9dccd3372 100644
--- a/powerauth-java-server/src/main/java/io/getlime/security/powerauth/app/server/service/behavior/tasks/OperationServiceBehavior.java
+++ b/powerauth-java-server/src/main/java/io/getlime/security/powerauth/app/server/service/behavior/tasks/OperationServiceBehavior.java
@@ -371,7 +371,7 @@ public OperationUserActionResponse attemptApproveOperation(OperationApproveReque
 
             final String expectedUserId = operationEntity.getUserId();
             if (expectedUserId == null) {
-                logger.warn("Operation cannot be approved, because user ID is not set: {}.", operationId);
+                logger.warn("Operation ID: {} cannot be approved, because user ID is not set.", operationId);
                 throw localizationProvider.buildExceptionForCode(ServiceError.OPERATION_APPROVE_FAILURE);
             }