diff --git a/include/pocketpy/expr.h b/include/pocketpy/expr.h
index b5df6f58..6d5afbdd 100644
--- a/include/pocketpy/expr.h
+++ b/include/pocketpy/expr.h
@@ -363,7 +363,7 @@ struct BinaryExpr: Expr{
     Expr_ lhs;
     Expr_ rhs;
     bool is_compare() const override;
-    void _emit_compare(CodeEmitContext* ctx, pod_vector<int>& jmps);
+    void _emit_compare(CodeEmitContext*, small_vector_2<int, 6>&);
     void emit_(CodeEmitContext* ctx) override;
 };
 
diff --git a/src/expr.cpp b/src/expr.cpp
index 974a1bfb..5faa5f8b 100644
--- a/src/expr.cpp
+++ b/src/expr.cpp
@@ -659,7 +659,7 @@ namespace pkpy{
         }
     }
 
-    void BinaryExpr::_emit_compare(CodeEmitContext* ctx, pod_vector<int>& jmps){
+    void BinaryExpr::_emit_compare(CodeEmitContext* ctx, small_vector_2<int, 6>& jmps){
         if(lhs->is_compare()){
             static_cast<BinaryExpr*>(lhs.get())->_emit_compare(ctx, jmps);
         }else{
@@ -683,7 +683,7 @@ namespace pkpy{
     }
 
     void BinaryExpr::emit_(CodeEmitContext* ctx) {
-        pod_vector<int> jmps;
+        small_vector_2<int, 6> jmps;
         if(is_compare() && lhs->is_compare()){
             // (a < b) < c
             static_cast<BinaryExpr*>(lhs.get())->_emit_compare(ctx, jmps);
diff --git a/src/vm.cpp b/src/vm.cpp
index 0495e549..e1a9ab8f 100644
--- a/src/vm.cpp
+++ b/src/vm.cpp
@@ -715,7 +715,7 @@ Str VM::disassemble(CodeObject_ co){
         return s + std::string(n - s.length(), ' ');
     };
 
-    pod_vector<int> jumpTargets;
+    std::vector<int> jumpTargets;
     for(auto byte : co->codes){
         if(byte.op == OP_JUMP_ABSOLUTE || byte.op == OP_POP_JUMP_IF_FALSE || byte.op == OP_SHORTCUT_IF_FALSE_OR_POP || byte.op == OP_LOOP_CONTINUE){
             jumpTargets.push_back(byte.arg);