diff --git a/pipelined/src/lsu/lsu.sv b/pipelined/src/lsu/lsu.sv
index cb37e1ef..9c99134f 100644
--- a/pipelined/src/lsu/lsu.sv
+++ b/pipelined/src/lsu/lsu.sv
@@ -266,7 +266,7 @@ module lsu (
   end
 
   if (`F_SUPPORTED) 
-    mux2 #(`LLEN) datamux({{`LLEN/`XLEN}{IMAWriteDataM}}, FWriteDataM, FpLoadStoreM, IMAFWriteDataM);
+    mux2 #(`LLEN) datamux({{{`LLEN-`XLEN}{1'b0}}, IMAWriteDataM}, FWriteDataM, FpLoadStoreM, IMAFWriteDataM);
   else assign IMAFWriteDataM = IMAWriteDataM;
   
   /////////////////////////////////////////////////////////////////////////////////////////////