diff --git a/Data/include/Poco/Data/Extraction.h b/Data/include/Poco/Data/Extraction.h
index 81153c979..9594e5022 100644
--- a/Data/include/Poco/Data/Extraction.h
+++ b/Data/include/Poco/Data/Extraction.h
@@ -90,7 +90,8 @@ public:
 		AbstractExtraction(Limit::LIMIT_UNLIMITED, pos.value()),
 		_rResult(rResult), 
 		_default(), 
-		_extracted(false)
+		_extracted(false),
+		_null(false)
 		/// Creates an Extraction object at specified position.
 		/// Uses an empty object T as default value.
 	{
@@ -100,7 +101,8 @@ public:
 		AbstractExtraction(Limit::LIMIT_UNLIMITED, pos.value()),
 		_rResult(rResult), 
 		_default(def), 
-		_extracted(false)
+		_extracted(false),
+		_null(false)
 		/// Creates an Extraction object at specified position.
 		/// Uses the provided def object as default value.
 	{