diff --git a/wa/instruments/trace_cmd.py b/wa/instruments/trace_cmd.py
index fbc4a2ad..c2f5438e 100644
--- a/wa/instruments/trace_cmd.py
+++ b/wa/instruments/trace_cmd.py
@@ -222,7 +222,9 @@ class TraceCmdInstrument(Instrument):
             raise InstrumentError('trace-cmd is not in PATH; is it installed?')
 
     def mark_start(self, context):
-        self.collector.mark_start()
+        if self.is_enabled:
+            self.collector.mark_start()
 
     def mark_stop(self, context):
-        self.collector.mark_stop()
+        if self.is_enabled:
+            self.collector.mark_stop()