diff --git a/performance/measure_circuit.py b/performance/measure_circuit.py
index 8535867..1c4cf6f 100644
--- a/performance/measure_circuit.py
+++ b/performance/measure_circuit.py
@@ -25,6 +25,6 @@ def execution_statistics(circuits, state, scale=1, **kwargs):
     results /= scale
     N = len(results)
     avg = np.average(results)
-    std_dev = np.std(results)
+    std_dev = np.std(results) / np.sqrt(N)
 
     return N, avg, std_dev