diff --git a/src/exec.c b/src/exec.c
index 7457ef1..a578659 100644
--- a/src/exec.c
+++ b/src/exec.c
@@ -23,11 +23,6 @@ ASTNumData exec_call(AST* ast) {
     ASTCallData* calldata = (ASTCallData*)ast->data;
     if (!strcmp(calldata->to, "+") && calldata->argc == 2) {
 
-        /*
-        ASTNumData* n1 = (ASTNumData*)calldata->argv[0]->data;
-        ASTNumData* n2 = (ASTNumData*)calldata->argv[1]->data;
-        */
-
         ASTNumData n1 = exec_expr(calldata->argv[0]);
         ASTNumData n2 = exec_expr(calldata->argv[1]);
 
@@ -37,6 +32,11 @@ ASTNumData exec_call(AST* ast) {
         ASTNumData n2 = exec_expr(calldata->argv[1]);
 
         return n1 - n2;
+    } else if (!strcmp(calldata->to, "*") && calldata->argc == 2) {
+        ASTNumData n1 = exec_expr(calldata->argv[0]);
+        ASTNumData n2 = exec_expr(calldata->argv[1]);
+
+        return n1 * n2;
     }
     return -1000;
 }
diff --git a/src/grammar.y b/src/grammar.y
index 862a6d9..8b3d0de 100644
--- a/src/grammar.y
+++ b/src/grammar.y
@@ -21,10 +21,13 @@
 
 %define parse.error verbose
 
-%token<fval> NUM
-%token NEG
 %token<strval> CALL
+%token<fval> NUM
+
+%token NEG
 %token PLUS
+%token MULT
+
 %token NL
 %type<ast> exp
 
@@ -63,4 +66,29 @@ exp:
         $$ = ast_init(AST_TYPE_CALL, ast_call_data_init("-", 2, argv));
     }
 
+    | NUM MULT NUM {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = ast_init(AST_TYPE_NUM, ast_num_data_init($1));
+        argv[1] = ast_init(AST_TYPE_NUM, ast_num_data_init($3));
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init("*", 2, argv));
+    }
+    | NEG NUM MULT NUM {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = ast_init(AST_TYPE_NUM, ast_num_data_init(-$2));
+        argv[1] = ast_init(AST_TYPE_NUM, ast_num_data_init($4));
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init("*", 2, argv));
+    }
+    | NEG NUM MULT NEG NUM {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = ast_init(AST_TYPE_NUM, ast_num_data_init(-$2));
+        argv[1] = ast_init(AST_TYPE_NUM, ast_num_data_init(-$5));
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init("*", 2, argv));
+    }
+    | NUM MULT NEG NUM {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = ast_init(AST_TYPE_NUM, ast_num_data_init($1));
+        argv[1] = ast_init(AST_TYPE_NUM, ast_num_data_init(-$4));
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init("*", 2, argv));
+    }
+
 %%
diff --git a/src/lexer.c b/src/lexer.c
index 9313c75..899f05d 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -66,6 +66,7 @@ int yylex() {
         case '+':  return PLUS;
         case '\n': return NL;
         case '-':  return NEG;
+        case '*':  return MULT;
         default:   return CALL;
     }