diff --git a/src/main/java/sc/fiji/snt/annotation/AllenCompartment.java b/src/main/java/sc/fiji/snt/annotation/AllenCompartment.java
index af1acc999..bfcbfd59f 100644
--- a/src/main/java/sc/fiji/snt/annotation/AllenCompartment.java
+++ b/src/main/java/sc/fiji/snt/annotation/AllenCompartment.java
@@ -177,7 +177,7 @@ private boolean isChildOfWithoutChecks(final AllenCompartment parent) {
 		final int parentIdxInPath = childStructureIdPath.lastIndexOf("/" + parentIdString + "/");
 		if (parentIdxInPath == -1)
 			return false;
-		return Arrays.stream(childStructureIdPath.substring(parentIdxInPath + parentIdString.length()).split("/"))
+		return Arrays.stream(childStructureIdPath.substring(parentIdxInPath + parentIdString.length() + 1).split("/"))
 				.filter(s -> !s.isEmpty())
 				.map(Integer::parseInt)
 				.anyMatch(id -> id == id());