diff --git a/SimG4Components/src/SimG4SaveSmearedParticles.h b/SimG4Components/src/SimG4SaveSmearedParticles.h
index acaaad2..4fdd0ee 100644
--- a/SimG4Components/src/SimG4SaveSmearedParticles.h
+++ b/SimG4Components/src/SimG4SaveSmearedParticles.h
@@ -8,10 +8,11 @@
 #include "k4FWCore/DataHandle.h"
 #include "SimG4Interface/ISimG4SaveOutputTool.h"
 
+#include "edm4hep/MCRecoParticleAssociationCollection.h"
+
 // datamodel
 namespace edm4hep {
 class ReconstructedParticleCollection;
-class MCRecoParticleAssociationCollection;
 }
 
 /** @class SimG4SaveSmearedParticles SimG4Components/src/SimG4SaveSmearedParticles.h SimG4SaveSmearedParticles.h
diff --git a/SimG4Fast/src/components/SimG4FastSimHistograms.h b/SimG4Fast/src/components/SimG4FastSimHistograms.h
index b7ae230..7f27ec8 100644
--- a/SimG4Fast/src/components/SimG4FastSimHistograms.h
+++ b/SimG4Fast/src/components/SimG4FastSimHistograms.h
@@ -8,10 +8,11 @@
 #include "k4FWCore/DataHandle.h"
 class ITHistSvc;
 
+#include "edm4hep/MCRecoParticleAssociationCollection.h"
+
 // datamodel
 namespace edm4hep {
 class ReconstructedParticleCollection;
-class MCRecoParticleAssociationCollection;
 }
 
 class TH1F;