diff --git a/src/plugins/debugger/gdb/attachgdbadapter.cpp b/src/plugins/debugger/gdb/attachgdbadapter.cpp
index 17929624ffecc6f3174be782d1a85a6e6b95334f..0803d3a5f53cb06078acdedd7edcd79347f9eb5c 100644
--- a/src/plugins/debugger/gdb/attachgdbadapter.cpp
+++ b/src/plugins/debugger/gdb/attachgdbadapter.cpp
@@ -92,6 +92,7 @@ void AttachGdbAdapter::handleAttach(const GdbResponse &response)
 void AttachGdbAdapter::interruptInferior()
 {
     const qint64 pid = startParameters().attachPID;
+    QTC_ASSERT(pid > 0, return);
     if (!interruptProcess(pid))
         debugMessage(_("CANNOT INTERRUPT %1").arg(pid));
 }
diff --git a/src/plugins/debugger/gdb/termgdbadapter.cpp b/src/plugins/debugger/gdb/termgdbadapter.cpp
index 6380d259cbae194446c2d9d9b861019fe3b4d1b3..fbdc6a6dd84c3ab8d885f46d636efa893e052deb 100644
--- a/src/plugins/debugger/gdb/termgdbadapter.cpp
+++ b/src/plugins/debugger/gdb/termgdbadapter.cpp
@@ -132,6 +132,7 @@ void TermGdbAdapter::startInferiorPhase2()
 void TermGdbAdapter::interruptInferior()
 {
     const qint64 attachedPID = m_engine->inferiorPid();
+    QTC_ASSERT(attachedPID > 0, return);
     if (!interruptProcess(attachedPID))
         debugMessage(_("CANNOT INTERRUPT %1").arg(attachedPID));
 }