diff --git a/src/calc.js b/src/calc.js
index 2a1efb6..d3f3e2a 100644
--- a/src/calc.js
+++ b/src/calc.js
@@ -244,6 +244,7 @@ function compute(op, a, b) {
     case '*': return a * b;
     case '%': return a % b;
     case '|': return a | b;
+    case '&': return a & b;
     case '<': return a < b;
     case '>': return a > b;
     case '^': return Math.pow(a, b);