diff --git a/repos/base-nova/src/core/include/platform_thread.h b/repos/base-nova/src/core/include/platform_thread.h
index e551c53490..a17e07f502 100644
--- a/repos/base-nova/src/core/include/platform_thread.h
+++ b/repos/base-nova/src/core/include/platform_thread.h
@@ -53,9 +53,9 @@ namespace Genode {
 			addr_t _sel_sc()     const { return _id_base + 2; }
 
 			/* convenience function to access _feature variable */
-			inline bool is_main_thread() { return _features & MAIN_THREAD; }
-			inline bool is_vcpu()        { return _features & VCPU; }
-			inline bool is_worker()      { return _features & WORKER; }
+			inline bool is_main_thread() const { return _features & MAIN_THREAD; }
+			inline bool is_vcpu()        const { return _features & VCPU; }
+			inline bool is_worker()      const { return _features & WORKER; }
 
 		public:
 
diff --git a/repos/base-nova/src/core/platform_thread.cc b/repos/base-nova/src/core/platform_thread.cc
index 439d435525..aa375a4552 100644
--- a/repos/base-nova/src/core/platform_thread.cc
+++ b/repos/base-nova/src/core/platform_thread.cc
@@ -324,11 +324,15 @@ unsigned long long Platform_thread::execution_time() const
 	unsigned long long time = 0;
 
 	/*
-	 * Ignore the return value, which indicates success only for global ECs.
 	 * For local ECs, we simply return 0 as local ECs are executed with the
 	 * time of their callers.
 	 */
-	(void) Nova::sc_ctrl(_sel_sc(), time);
+	if (is_worker())
+		return time;
+
+	uint8_t res = Nova::sc_ctrl(_sel_sc(), time);
+	if (res != Nova::NOVA_OK)
+		PDBG("sc_ctrl failed res=%x", res);
 
 	return time;
 }