diff --git a/picorv32.v b/picorv32.v
index 88443b2..8ea791c 100644
--- a/picorv32.v
+++ b/picorv32.v
@@ -498,9 +498,11 @@ module picorv32 #(
 		end else begin
 			if (mem_la_read || mem_la_write) begin
 				mem_addr <= mem_la_addr;
-				mem_wdata <= mem_la_wdata;
 				mem_wstrb <= mem_la_wstrb & {4{mem_la_write}};
 			end
+            if (mem_la_write) begin
+				mem_wdata <= mem_la_wdata;
+            end
 			case (mem_state)
 				0: begin
 					if (mem_do_prefetch || mem_do_rinst || mem_do_rdata) begin