diff --git a/nasal_gc.h b/nasal_gc.h
index a051106..66be80b 100644
--- a/nasal_gc.h
+++ b/nasal_gc.h
@@ -122,13 +122,13 @@ struct nasal_hash
 
 struct nasal_func
 {
-    int32_t  dynpara;                            // dynamic parameter name index in hash.
-    uint32_t entry;                              // pc will set to entry-1 to call this function
-    uint32_t psize;                              // used to load default parameters to a new function
-    uint32_t lsize;                              // used to expand memory space for local values on stack
-    std::vector<nasal_ref> local;                // local scope with default value(nasal_ref)
-    std::vector<nasal_ref> upvalue;              // closure
-    std::unordered_map<std::string,size_t> keys; // parameter name table, size_t begins from 1
+    int32_t  dynpara;                           // dynamic parameter name index in hash.
+    uint32_t entry;                             // pc will set to entry-1 to call this function
+    uint32_t psize;                             // used to load default parameters to a new function
+    uint32_t lsize;                             // used to expand memory space for local values on stack
+    std::vector<nasal_ref> local;               // local scope with default value(nasal_ref)
+    std::vector<nasal_ref> upvalue;             // closure
+    std::unordered_map<uint32_t,uint32_t> keys; // parameter name table, size_t begins from 1
 
     nasal_func():dynpara(-1),entry(0),psize(0),lsize(0){}
     void clear();
diff --git a/nasal_vm.h b/nasal_vm.h
index 62e06d1..f484279 100644
--- a/nasal_vm.h
+++ b/nasal_vm.h
@@ -440,7 +440,7 @@ inline void nasal_vm::opr_para()
 {
     nasal_func& func=top[0].func();
     // func->size has 1 place reserved for "me"
-    func.keys[str_table[imm[pc]]]=func.psize;
+    func.keys[imm[pc]]=func.psize;
     func.local[func.psize++]={vm_none};
 }
 inline void nasal_vm::opr_deft()
@@ -448,7 +448,7 @@ inline void nasal_vm::opr_deft()
     nasal_ref val=top[0];
     nasal_func& func=(--top)[0].func();
     // func->size has 1 place reserved for "me"
-    func.keys[str_table[imm[pc]]]=func.psize;
+    func.keys[imm[pc]]=func.psize;
     func.local[func.psize++]=val;
 }
 inline void nasal_vm::opr_dyn()
@@ -779,10 +779,11 @@ inline void nasal_vm::opr_callfh()
     
     for(auto& i:func.keys)
     {
-        if(hash.count(i.first))
-            local[i.second]=hash[i.first];
+        const std::string& key=str_table[i.first];
+        if(hash.count(key))
+            local[i.second]=hash[key];
         else if(local[i.second].type==vm_none)
-            die("callfh: lack argument(s): \""+i.first+"\"");
+            die("callfh: lack argument(s): \""+key+"\"");
     }
 
     top[0]=upvalr;
diff --git a/test/scalar.nas b/test/scalar.nas
index d208c8f..d9350f4 100644
--- a/test/scalar.nas
+++ b/test/scalar.nas
@@ -201,4 +201,7 @@ foreach(var i;a){
 foreach(i;a){
     ;
 }
-println(runtime.argv());
\ No newline at end of file
+println(runtime.argv());
+func(a,b,c,d="只有红茶可以吗"){
+    println(a,' ',b,' ',c,' ',d);
+}(c:1919810,b:514,a:114);
\ No newline at end of file