diff --git a/miniscm/miniscm.c b/miniscm/miniscm.c
index d2ec49f..315ed8e 100644
--- a/miniscm/miniscm.c
+++ b/miniscm/miniscm.c
@@ -1218,6 +1218,8 @@ register pointer a, b;
 #define OP_STRINGREF            112
 #define OP_STRINGLEN            113
 #define OP_LIST2STRING          114
+#define OP_STRING2SYMBOL        115
+#define OP_SYMBOL2STRING        116
 
 static FILE *tmpfp;
 static int tok;
@@ -1783,6 +1785,16 @@ register short op;
 		} else {
 			Error_0("char->integer: argument must be char");
 		}
+	case OP_STRING2SYMBOL: /* string->symbol */
+		if (!isstring(car(args))) {
+			Error_0("string->symbol: argument must be string");
+		}
+		s_return(mk_symbol(strvalue(car(args))));
+	case OP_SYMBOL2STRING: /* symbol->string */
+		if (!issymbol(car(args))) {
+			Error_0("symbol->string: argument must by symbol");
+		}
+		s_return(mk_string(symname(car(args))));
 
 	default:
 		sprintf(strbuff, "%d is illegal operator", operator);
@@ -2529,7 +2541,9 @@ pointer	(*dispatch_table[])() = {
 	opexe_2,        /* OP_CHAR2INT */
 	opexe_4,        /* OP_STRINGREF */
 	opexe_4,        /* OP_STRINGLEN */
-	opexe_list2string         /* OP_LIST2STRING */
+	opexe_list2string,         /* OP_LIST2STRING */
+	opexe_2,         /* OP_STRING2SYMBOL */
+	opexe_2          /* OP_SYMBOL2STRING */
 };
 
 
@@ -2692,6 +2706,8 @@ init_procs()
 	mk_proc(OP_STRINGREF, "string-ref");
 	mk_proc(OP_STRINGLEN, "string-length");
 	mk_proc(OP_LIST2STRING, "list->string");
+	mk_proc(OP_STRING2SYMBOL, "string->symbol");
+	mk_proc(OP_SYMBOL2STRING, "symbol->string");
 }