diff --git a/src/cs_gen.cc b/src/cs_gen.cc
index d871b38..ddde6f3 100644
--- a/src/cs_gen.cc
+++ b/src/cs_gen.cc
@@ -583,10 +583,6 @@ static void compileblockmain(codegen_state &gs, int wordtype) {
                     throw error{gs.ts, "too many @s"};
                     return;
                 }
-                if (concs + 2 > MAX_ARGUMENTS) {
-                    gs.code.push_back(BC_INST_CONC_W | BC_RET_STRING | (concs << 8));
-                    concs = 1;
-                }
                 if (compileblockstr(gs, start, esc)) {
                     concs++;
                 }
diff --git a/src/cs_vm.cc b/src/cs_vm.cc
index 7b9a13c..5e1cf34 100644
--- a/src/cs_vm.cc
+++ b/src/cs_vm.cc
@@ -917,7 +917,8 @@ std::uint32_t *vm_exec(
                     ((op & BC_INST_OP_MASK) == BC_INST_CONC) ? " " : ""
                 );
                 args.resize(args.size() - numconc, any_value{cs});
-                force_arg(args.emplace_back(cs), op & BC_INST_RET_MASK);
+                args.emplace_back(cs).set_str(buf);
+                force_arg(args.back(), op & BC_INST_RET_MASK);
                 continue;
             }