diff --git a/src/main/jastadd/base/io/IoPN.jadd b/src/main/jastadd/base/io/IoPN.jadd
index bc1c7bdb42e2141be8c82d7a8dce5c2e1260fede..84b3fdcebe62065de014bd2487589ac592103da8 100644
--- a/src/main/jastadd/base/io/IoPN.jadd
+++ b/src/main/jastadd/base/io/IoPN.jadd
@@ -7,4 +7,8 @@ aspect IoPnExtension{
         inh DinerosTransition TransitionInformation.containingTransition();
         eq DinerosTransition.getChild().containingTransition() = this;
 
+        syn InputSignalClause SignalTransitionInformation.getClause() {
+            return ToolSpecificsParser.getClauseFromToolSpecifics(containingTransition().getToolspecificList());
+        }
+
 }
diff --git a/src/main/jastadd/base/io/IoPN.relast b/src/main/jastadd/base/io/IoPN.relast
index f80c79bd4163d0805db12e2c789d7a3bd36bf4f1..ab86c6a23431ca4f9b3fa07c83987a524f4b31a0 100644
--- a/src/main/jastadd/base/io/IoPN.relast
+++ b/src/main/jastadd/base/io/IoPN.relast
@@ -10,7 +10,7 @@ PlaceInformation : PnObjectInformation;
 abstract TransitionInformation : PnObjectInformation;
 TopicTransitionInformation : TransitionInformation ::= <Topic:String> SubscriberPort:SubscriberPort* PublisherPort:PublisherPort*;
 ServiceTransitionInformation : TransitionInformation ::= <ServiceName:String> ServerChannel:ServiceChannel ClientChannel:ServiceChannel*;
-SignalTransitionInformation : TransitionInformation ::= Clause:InputSignalClause; /* only normal transition have signals attached */
+SignalTransitionInformation : TransitionInformation ::= /Clause:InputSignalClause/; /* only normal transition have signals attached */
 
 // Ports
 abstract Port;