diff --git a/src/Simulation/Simulators/OpenSystemsSimulator/Decompositions/Utils.qs b/src/Simulation/Simulators/OpenSystemsSimulator/Decompositions/Utils.qs
index 308af8341b7..8bf129733d9 100644
--- a/src/Simulation/Simulators/OpenSystemsSimulator/Decompositions/Utils.qs
+++ b/src/Simulation/Simulators/OpenSystemsSimulator/Decompositions/Utils.qs
@@ -135,12 +135,12 @@ namespace Microsoft.Quantum.Experimental.Decompositions {
 
     internal operation SpreadZ (from : Qubit, to : Qubit[]) : Unit is Adj {
         if (Length(to) > 0) {
-            Controlled Intrinsic.X([to[0]], from);
             if (Length(to) > 1) {
                 let half = Length(to) / 2;
                 SpreadZ(to[0], to[half + 1 .. Length(to) - 1]);
                 SpreadZ(from, to[1 .. half]);
             }
+            Controlled Intrinsic.X([to[0]], from);
         }
     }