diff --git a/src/main/scala/millfork/node/CallGraph.scala b/src/main/scala/millfork/node/CallGraph.scala
index 1b92401f..64949272 100644
--- a/src/main/scala/millfork/node/CallGraph.scala
+++ b/src/main/scala/millfork/node/CallGraph.scala
@@ -37,6 +37,7 @@ abstract class CallGraph(program: Program) {
   entryPoints += "main"
   program.declarations.foreach(s => add(None, Nil, s))
   everCalledFunctions.retain(allFunctions)
+  fillOut()
 
   def add(currentFunction: Option[String], callingFunctions: List[String], node: Node): Unit = {
     node match {