diff --git a/lib/circuit.js b/lib/circuit.js
index 42f1e338..2dc50c80 100644
--- a/lib/circuit.js
+++ b/lib/circuit.js
@@ -9,7 +9,8 @@ const fallbackFunction = Symbol('fallback');
 
 class CircuitBreaker {
   constructor (action, options) {
-    this.action = action;
+    if (typeof action !== 'function') this.action = () => action;
+    else this.action = action;
     this.options = options;
     this.status = new Status();
     this.Promise = options.Promise;
@@ -35,8 +36,10 @@ class CircuitBreaker {
   }
 
   fire () {
+    const args = Array.prototype.slice.call(arguments);
+
     if (this.open || (this.halfOpen && this[halfOpenAttempted])) {
-      return failFast(this, Array.prototype.slice.call(arguments));
+      return failFast(this, args);
     }
 
     this[halfOpenAttempted] = this.halfOpen;
@@ -47,7 +50,7 @@ class CircuitBreaker {
       },
       this.options.timeout);
 
-      this.action.apply(this.action, arguments)
+      this.Promise.resolve(this.action.apply(this.action, args))
         .then((result) => {
           succeed(this);
           resolve(result);
diff --git a/test/test.js b/test/test.js
index 806172e3..1151457e 100644
--- a/test/test.js
+++ b/test/test.js
@@ -25,6 +25,33 @@ test('Passes arguments to the circuit function', (t) => {
     .catch(t.fail);
 });
 
+test('Works with functions that do not return a promise', (t) => {
+  const breaker = circuitBreaker(nonPromise);
+
+  breaker.fire()
+    .then((arg) => t.equals(arg, 'foo'))
+    .then(t.end)
+    .catch(t.fail);
+});
+
+test('Works with non-functions', (t) => {
+  const breaker = circuitBreaker('foobar');
+
+  breaker.fire()
+    .then((arg) => t.equals(arg, 'foobar'))
+    .then(t.end)
+    .catch(t.fail);
+});
+
+test.skip('Works with callback functions', (t) => {
+  const breaker = circuitBreaker(callbackFunction);
+
+  breaker.fire(3, 4)
+    .then((arg) => t.equals(arg, 7))
+    .then(t.end)
+    .catch(t.fail);
+});
+
 test('Fails when the circuit function fails', (t) => {
   const expected = -1;
   const breaker = circuitBreaker(passFail);
@@ -136,3 +163,10 @@ function slowFunction () {
   });
 }
 
+function nonPromise () {
+  return 'foo';
+}
+
+function callbackFunction (x, y, callback) {
+  callback(x + y);
+}