diff --git a/src/add-ons/tracker/zipomatic/GenericThread.cpp b/src/add-ons/tracker/zipomatic/GenericThread.cpp
index a83aefa8c3..345dcf1578 100644
--- a/src/add-ons/tracker/zipomatic/GenericThread.cpp
+++ b/src/add-ons/tracker/zipomatic/GenericThread.cpp
@@ -59,6 +59,7 @@ GenericThread::ThreadFunction()
 			}
 			
 			delete this;
+			return B_OK;
 		}
 
 		BeginUnit();
diff --git a/src/apps/expander/GenericThread.cpp b/src/apps/expander/GenericThread.cpp
index 5ddcacd17b..76ffcf92e5 100644
--- a/src/apps/expander/GenericThread.cpp
+++ b/src/apps/expander/GenericThread.cpp
@@ -52,6 +52,7 @@ GenericThread::ThreadFunction(void)
 			}
 
 			delete this;		// destructor
+			return B_OK;
 		}
 
 		BeginUnit();