diff --git a/powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll b/powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll
index 3dbb3d448da..eec6dd5b66f 100644
--- a/powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll
+++ b/powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll
@@ -727,7 +727,7 @@ module Trees {
     }
   }
 
-  class CmdExprTree extends StandardPreOrderTree instanceof CmdExpr {
+  class CmdExprTree extends StandardPostOrderTree instanceof CmdExpr {
     override AstNode getChildNode(int i) { i = 0 and result = super.getExpr() }
   }