diff --git a/backends/firrtl/firrtl.cc b/backends/firrtl/firrtl.cc
index 3b61eb9f..0d1c1889 100644
--- a/backends/firrtl/firrtl.cc
+++ b/backends/firrtl/firrtl.cc
@@ -280,6 +280,7 @@ struct FirrtlWorker
 					cell_exprs.push_back(stringf("    %s.w%d.addr <= %s\n", mem_id.c_str(), i, addr_expr.c_str()));
 					cell_exprs.push_back(stringf("    %s.w%d.data <= %s\n", mem_id.c_str(), i, data_expr.c_str()));
 					cell_exprs.push_back(stringf("    %s.w%d.en <= %s\n", mem_id.c_str(), i, wen_expr.c_str()));
+					cell_exprs.push_back(stringf("    %s.w%d.mask <= UInt<1>(1)\n", mem_id.c_str(), i));
 					cell_exprs.push_back(stringf("    %s.w%d.clk <= asClock(%s)\n", mem_id.c_str(), i, clk_expr.c_str()));
 				}