diff --git a/src/cs_state.cc b/src/cs_state.cc
index b9bb8e2..4cbb272 100644
--- a/src/cs_state.cc
+++ b/src/cs_state.cc
@@ -45,11 +45,17 @@ static void *default_alloc(void *, void *p, size_t, size_t ns) {
 }
 
 ident *internal_state::lookup_ident(std::size_t idx) {
+    if (idx < MAX_ARGUMENTS) {
+        return argmap[idx];
+    }
     std::lock_guard<std::mutex> l{ident_mtx};
     return identmap[idx];
 }
 
 ident const *internal_state::lookup_ident(std::size_t idx) const {
+    if (idx < MAX_ARGUMENTS) {
+        return argmap[idx];
+    }
     std::lock_guard<std::mutex> l{ident_mtx};
     return identmap[idx];
 }
@@ -141,7 +147,7 @@ state::state(alloc_func func, void *data) {
     for (std::size_t i = 0; i < MAX_ARGUMENTS; ++i) {
         char buf[16];
         snprintf(buf, sizeof(buf), "arg%zu", i + 1);
-        statep->new_ident(
+        statep->argmap[i] = &statep->new_ident(
             *this, static_cast<char const *>(buf), IDENT_FLAG_ARG
         );
     }
diff --git a/src/cs_state.hh b/src/cs_state.hh
index ac4fa8c..a2c718e 100644
--- a/src/cs_state.hh
+++ b/src/cs_state.hh
@@ -50,6 +50,7 @@ struct internal_state {
         allocator_type
     > idents;
     std::vector<ident *, std_allocator<ident *>> identmap;
+    std::array<ident *, MAX_ARGUMENTS> argmap;
     mutable std::mutex ident_mtx;
 
     string_pool *strman;
diff --git a/src/cs_vm.cc b/src/cs_vm.cc
index 2053259..6b1d51b 100644
--- a/src/cs_vm.cc
+++ b/src/cs_vm.cc
@@ -133,7 +133,7 @@ any_value exec_alias(
     std::size_t noff = ts.idstack.size();
     for(std::size_t i = 0; i < callargs; i++) {
         auto &ast = ts.get_astack(
-            static_cast<alias *>(ts.istate->lookup_ident(i))
+            static_cast<alias *>(ts.istate->argmap[i])
         );
         auto &st = ts.idstack.emplace_back();
         ast.push(st);
@@ -167,14 +167,14 @@ any_value exec_alias(
         tss.ident_flags = oflags;
         for (std::size_t i = 0; i < cargs; i++) {
             tss.get_astack(
-                static_cast<alias *>(tss.istate->lookup_ident(i))
+                static_cast<alias *>(tss.istate->argmap[i])
             ).pop();
             amask[i] = false;
         }
         for (; amask.any(); ++cargs) {
             if (amask[cargs]) {
                 tss.get_astack(
-                    static_cast<alias *>(tss.istate->lookup_ident(cargs))
+                    static_cast<alias *>(tss.istate->argmap[cargs])
                 ).pop();
                 amask[cargs] = false;
             }
@@ -202,7 +202,7 @@ any_value exec_code_with_args(thread_state &ts, bcode_ref const &body) {
     for (std::size_t i = 0; mask.any(); ++i) {
         if (mask[0]) {
             auto &ast = ts.get_astack(
-                static_cast<alias *>(ts.istate->lookup_ident(i))
+                static_cast<alias *>(ts.istate->argmap[i])
             );
             auto &st = ts.idstack.emplace_back();
             st.next = ast.node;
@@ -229,7 +229,7 @@ any_value exec_code_with_args(thread_state &ts, bcode_ref const &body) {
         for (std::size_t i = 0, nredo = 0; mask2.any(); ++i) {
             if (mask2[0]) {
                 tss.get_astack(
-                    static_cast<alias *>(tss.istate->lookup_ident(i))
+                    static_cast<alias *>(tss.istate->argmap[i])
                 ).node = tss.idstack[offn + nredo++].next;
             }
             mask2 >>= 1;