diff --git a/src/tools/qdoc/qdocindexfiles.cpp b/src/tools/qdoc/qdocindexfiles.cpp
index 466742ee3a..d7a51da952 100644
--- a/src/tools/qdoc/qdocindexfiles.cpp
+++ b/src/tools/qdoc/qdocindexfiles.cpp
@@ -64,6 +64,7 @@ QDocIndexFiles* QDocIndexFiles::qdocIndexFiles_ = NULL;
   Constructs the singleton QDocIndexFiles.
  */
 QDocIndexFiles::QDocIndexFiles()
+    : gen_( 0 )
 {
     qdb_ = QDocDatabase::qdocDB();
 }