diff --git a/Ghidra/Processors/x86/data/languages/x86-64-win.cspec b/Ghidra/Processors/x86/data/languages/x86-64-win.cspec
index d4813f1dd2..ee5e0edf55 100644
--- a/Ghidra/Processors/x86/data/languages/x86-64-win.cspec
+++ b/Ghidra/Processors/x86/data/languages/x86-64-win.cspec
@@ -158,6 +158,7 @@
       <range space="stack" first="8" last="39"/>
     </localrange>
   </prototype>
+  <modelalias name="__cdecl" parent="__fastcall"/>
   <callfixup name="alloca_probe">
     <target name="_alloca_probe"/>
     <target name="_alloca_probe2"/>