diff --git a/libs/main/core/pibase.h b/libs/main/core/pibase.h
index c8eff9d8..d015620e 100644
--- a/libs/main/core/pibase.h
+++ b/libs/main/core/pibase.h
@@ -868,6 +868,15 @@ template<> inline uint piHash(const float   & v) {return (uint)v;}
 template<> inline uint piHash(const double  & v) {return piHashData((const uchar *)&v, sizeof(v));}
 template<> inline uint piHash(const ldouble & v) {return piHashData((const uchar *)&v, sizeof(v));}
 
+template<typename T> inline void piDeleteAll(T & container) {
+	for (auto i: container)
+		delete i;
+}
+template<typename T> inline void piDeleteAllAndClear(T & container) {
+	piDeleteAll(container);
+	container.clear();
+}
+
 #define piRoundf piRound<float>
 #define piRoundd piRound<double>
 #define piComparef piCompare<float>
diff --git a/libs/main/core/piobject.cpp b/libs/main/core/piobject.cpp
index dd4eed43..f0cdfac6 100644
--- a/libs/main/core/piobject.cpp
+++ b/libs/main/core/piobject.cpp
@@ -194,6 +194,7 @@ PIObject::~PIObject() {
 	mutexObjects().unlock();
 	deleted(this);
 	piDisconnectAll();
+	_signature_ = 0;
 }