diff --git a/src/main/java/kieker/analysis/stage/tracediagnosis/OperationCallAggregator.java b/src/main/java/kieker/analysis/stage/tracediagnosis/OperationCallAggregator.java
index 3a35e4f5384d99714d9f590e6e8e531ac3545383..be13a08524a96d743af672bc00546734e9e9c67f 100644
--- a/src/main/java/kieker/analysis/stage/tracediagnosis/OperationCallAggregator.java
+++ b/src/main/java/kieker/analysis/stage/tracediagnosis/OperationCallAggregator.java
@@ -37,7 +37,7 @@ public final class OperationCallAggregator extends AbstractTransformation<Operat
 
 	@Override
 	protected void execute(final OperationCall call) {
-		final String key = call.getIdentifier();
+		final String key = call.getIdentifierWithFailure();
 
 		if (!this.aggregationMap.containsKey(key)) {
 			final List<OperationCall> aggregationList = new ArrayList<>();