diff --git a/repos/base-hw/src/core/spec/x86/kernel/cpu.cc b/repos/base-hw/src/core/spec/x86/kernel/cpu.cc
index 98e0aa7f25..eaf28f75b3 100644
--- a/repos/base-hw/src/core/spec/x86/kernel/cpu.cc
+++ b/repos/base-hw/src/core/spec/x86/kernel/cpu.cc
@@ -36,5 +36,7 @@ void Cpu_idle::exception(unsigned const cpu)
 		_interrupt(cpu);
 		return;
 	}
+	PWRN("Unknown exception %lu with error code %lu at ip=%p", trapno,
+	     errcode, (void *)ip);
 	assert(0);
 }