diff --git a/src/THcDriftChamber.cxx b/src/THcDriftChamber.cxx
index aec407120f71d0b7d059aad12ab0b3da32c1598b..9a53958fbb80e716f01b8279d509e3660c25a307 100644
--- a/src/THcDriftChamber.cxx
+++ b/src/THcDriftChamber.cxx
@@ -51,6 +51,16 @@ THcDriftChamber::THcDriftChamber(
   fHMSStyleChambers = 0;	// Default
 }
 
+//_____________________________________________________________________________
+THcDriftChamber::THcDriftChamber() :
+  THaSubDetector()
+{
+  // Constructor
+  fTrackProj = NULL;
+  fSpacePoints = NULL;
+  fIsInit = 0;
+
+}
 //_____________________________________________________________________________
 void THcDriftChamber::Setup(const char* name, const char* description)
 {
diff --git a/src/THcDriftChamber.h b/src/THcDriftChamber.h
index 7cb2f5e66fac030ec7a28f13780034970caa5c48..28e9b6a643f58aa43fdb5db6a0825b6b9c9874a3 100644
--- a/src/THcDriftChamber.h
+++ b/src/THcDriftChamber.h
@@ -55,6 +55,7 @@ public:
   //  friend class THaScCalib;
   void SetHMSStyleFlag(Int_t flag) {fHMSStyleChambers = flag;}
 
+  THcDriftChamber(); // for ROOT I/O
 protected:
   Int_t f;