diff --git a/parser/nodes.cc b/parser/nodes.cc
index 4e1b688..b3e19e1 100644
--- a/parser/nodes.cc
+++ b/parser/nodes.cc
@@ -74,6 +74,9 @@ NodeRef BinOpNode::evaluate()
         case '-':
             r = o - t;
             break;
+        case '%':
+            r = (int) o % (int) t;
+            break;
         default:
             cerr << "Error: BinOpNode created with op '" << m_op << "'" << endl;
             exit(-3);
@@ -162,10 +165,6 @@ NodeRef ForNode::evaluate()
         }
     }
 
-    /* clear out all child nodes so that evaluateChildren() doesn't
-     * attempt to evaluate them */
-    m_children.clear();
-
     return eval;
 }
 
diff --git a/parser/parser.yy b/parser/parser.yy
index c42cbd4..7c89203 100644
--- a/parser/parser.yy
+++ b/parser/parser.yy
@@ -119,7 +119,7 @@ refptr<Scope> parser_scope;
 
 %right ASSIGN
 %left PLUS MINUS
-%left TIMES DIVIDE
+%left TIMES DIVIDE MOD
 %left UMINUS
 
 %%
@@ -587,6 +587,7 @@ vector3: LESS expression COMMA expression COMMA expression GREATER {
 expression: term                    { $$ = $1; }
           | expression TIMES term   { $$ = new BinOpNode('*', $1, $3); }
           | expression DIVIDE term  { $$ = new BinOpNode('/', $1, $3); }
+          | expression MOD term     { $$ = new BinOpNode('%', $1, $3); }
           | MINUS expression %prec UMINUS {
               $$ = new BinOpNode('-', new NumberNode(0.0), $2);
           }