diff --git a/io/io/src/TCollectionProxyFactory.cxx b/io/io/src/TCollectionProxyFactory.cxx
index 8599a29334bf0eae43faa6b144f87623836816aa..338dc6eea2c7a6365bdd15c1748e8ebd5778a1d5 100644
--- a/io/io/src/TCollectionProxyFactory.cxx
+++ b/io/io/src/TCollectionProxyFactory.cxx
@@ -146,7 +146,7 @@ TCollectionStreamer::TCollectionStreamer() : fStreamer(0)
    // Initializing constructor.
 }
 
-TCollectionStreamer::TCollectionStreamer(const TCollectionStreamer& c)
+TCollectionStreamer::TCollectionStreamer(const TCollectionStreamer& c) : fStreamer(0)
 {
    // Copy constructor.
    if ( c.fStreamer )  {