diff --git a/src_main/core/piobject.h b/src_main/core/piobject.h
index 4e6f7f8e..bddce621 100755
--- a/src_main/core/piobject.h
+++ b/src_main/core/piobject.h
@@ -637,8 +637,10 @@ public:
 					if (ts) i.dest_o->mutex_.lock();
 					i.dest_o->emitter_ = sender;
 					((void( *)(void * ))i.slot)(i.dest);
-					i.dest_o->emitter_ = 0;
-					if (ts) i.dest_o->mutex_.unlock();
+					if (i.dest_o->isPIObject()) {
+						i.dest_o->emitter_ = 0;
+						if (ts) i.dest_o->mutex_.unlock();
+					}
 				}
 #ifdef PIP_CXX11_SUPPORT
 			}
@@ -667,8 +669,10 @@ public:
 					i.dest_o->emitter_ = sender;
 					if (i.args_count == 0) ((void(*)(void *))i.slot)(i.dest);
 					else ((void(*)(void * , T0))i.slot)(i.dest, v0);
-					i.dest_o->emitter_ = 0;
-					if (ts) i.dest_o->mutex_.unlock();
+					if (i.dest_o->isPIObject()) {
+						i.dest_o->emitter_ = 0;
+						if (ts) i.dest_o->mutex_.unlock();
+					}
 				}
 #ifdef PIP_CXX11_SUPPORT
 			}
@@ -700,8 +704,10 @@ public:
 					case 1: ((void(*)(void * , T0))i.slot)(i.dest, v0); break;
 					default: ((void(*)(void * , T0, T1))i.slot)(i.dest, v0, v1); break;
 					}
-					i.dest_o->emitter_ = 0;
-					if (ts) i.dest_o->mutex_.unlock();
+					if (i.dest_o->isPIObject()) {
+						i.dest_o->emitter_ = 0;
+						if (ts) i.dest_o->mutex_.unlock();
+					}
 				}
 #ifdef PIP_CXX11_SUPPORT
 			}
@@ -735,8 +741,10 @@ public:
 					case 2: ((void(*)(void * , T0, T1))i.slot)(i.dest, v0, v1); break;
 					default: ((void(*)(void * , T0, T1, T2))i.slot)(i.dest, v0, v1, v2); break;
 					}
-					i.dest_o->emitter_ = 0;
-					if (ts) i.dest_o->mutex_.unlock();
+					if (i.dest_o->isPIObject()) {
+						i.dest_o->emitter_ = 0;
+						if (ts) i.dest_o->mutex_.unlock();
+					}
 				}
 #ifdef PIP_CXX11_SUPPORT
 			}
@@ -772,8 +780,10 @@ public:
 					case 3: ((void(*)(void * , T0, T1, T2))i.slot)(i.dest, v0, v1, v2); break;
 					default: ((void(*)(void * , T0, T1, T2, T3))i.slot)(i.dest, v0, v1, v2, v3); break;
 					}
-					i.dest_o->emitter_ = 0;
-					if (ts) i.dest_o->mutex_.unlock();
+					if (i.dest_o->isPIObject()) {
+						i.dest_o->emitter_ = 0;
+						if (ts) i.dest_o->mutex_.unlock();
+					}
 				}
 #ifdef PIP_CXX11_SUPPORT
 			}