diff --git a/compiler/arm/cgcpu.pas b/compiler/arm/cgcpu.pas
index d71341e5c4..4ee25254c0 100644
--- a/compiler/arm/cgcpu.pas
+++ b/compiler/arm/cgcpu.pas
@@ -1521,6 +1521,7 @@ unit cgcpu;
           begin
             list.Concat(taicpu.op_reg_reg(A_CLZ,dst,src));
             list.Concat(taicpu.op_reg_reg_const(A_RSB,dst,dst,31));
+            list.Concat(taicpu.op_reg_reg_const(A_AND,dst,dst,255));
           end
         else
           internalerror(201209041);