diff --git a/src/compiler/compile/css/Selector.ts b/src/compiler/compile/css/Selector.ts
index 225a901285..057ac482fd 100644
--- a/src/compiler/compile/css/Selector.ts
+++ b/src/compiler/compile/css/Selector.ts
@@ -89,7 +89,7 @@ function attribute_matches(node: Node, name: string, expected_value: string, ope
 
 function class_matches(node, name: string) {
 	return node.classes.some((class_directive) => {
-		return class_directive.name === name;
+		return new RegExp(`\\b${name}\\b`).test(class_directive.name);
 	});
 }
 
diff --git a/src/runtime/store/index.ts b/src/runtime/store/index.ts
index 21ff6ebe2c..abc8044b9b 100644
--- a/src/runtime/store/index.ts
+++ b/src/runtime/store/index.ts
@@ -10,7 +10,7 @@ type Unsubscriber = () => void;
 type Updater<T> = (value: T) => T;
 
 /** Cleanup logic callback. */
-type Invalidater<T> = (value?: T) => void;
+type Invalidator<T> = (value?: T) => void;
 
 /** Start and stop notification callbacks. */
 type StartStopNotifier<T> = (set: Subscriber<T>) => Unsubscriber | void;
@@ -22,7 +22,7 @@ export interface Readable<T> {
 	 * @param run subscription callback
 	 * @param invalidate cleanup callback
 	 */
-	subscribe(run: Subscriber<T>, invalidate?: Invalidater<T>): Unsubscriber;
+	subscribe(run: Subscriber<T>, invalidate?: Invalidator<T>): Unsubscriber;
 }
 
 /** Writable interface for both updating and subscribing. */
@@ -41,7 +41,7 @@ export interface Writable<T> extends Readable<T> {
 }
 
 /** Pair of subscriber and invalidator. */
-type SubscribeInvalidateTuple<T> = [Subscriber<T>, Invalidater<T>];
+type SubscribeInvalidateTuple<T> = [Subscriber<T>, Invalidator<T>];
 
 /**
  * Create a `Writable` store that allows both updating and reading by subscription.
@@ -67,7 +67,7 @@ export function writable<T>(value: T, start: StartStopNotifier<T> = noop): Writa
 		set(fn(value));
 	}
 
-	function subscribe(run: Subscriber<T>, invalidate: Invalidater<T> = noop): Unsubscriber {
+	function subscribe(run: Subscriber<T>, invalidate: Invalidator<T> = noop): Unsubscriber {
 		const subscriber: SubscribeInvalidateTuple<T> = [run, invalidate];
 		subscribers.push(subscriber);
 		if (subscribers.length === 1) {
@@ -127,7 +127,9 @@ export function derived<T, S extends Stores>(
 
 	const auto = fn.length < 2;
 
-	return readable(initial_value, (set) => {
+	const invalidators: Array<Invalidator<T>> = [];
+
+	const store = readable(initial_value, (set) => {
 		let inited = false;
 		const values: StoresValues<S> = [] as StoresValues<S>;
 
@@ -156,6 +158,7 @@ export function derived<T, S extends Stores>(
 				}
 			},
 			() => {
+				run_all(invalidators);
 				pending |= (1 << i);
 			}),
 		);
@@ -168,6 +171,22 @@ export function derived<T, S extends Stores>(
 			cleanup();
 		};
 	});
+
+	return {
+		subscribe(run: Subscriber<T>, invalidate: Invalidator<T> = noop): Unsubscriber {
+			invalidators.push(invalidate);
+
+			const unsubscribe = store.subscribe(run, invalidate);
+
+			return () => {
+				const index = invalidators.indexOf(invalidate);
+				if (index !== -1) {
+					invalidators.splice(index, 1);
+				}
+				unsubscribe();
+			};
+		}
+	}
 }
 
 /**
@@ -178,4 +197,4 @@ export function get<T>(store: Readable<T>): T {
 	let value: T | undefined;
 	store.subscribe((_: T) => value = _)();
 	return value as T;
-}
+}
\ No newline at end of file
diff --git a/test/css/samples/directive-special-character/expected.css b/test/css/samples/directive-special-character/expected.css
new file mode 100644
index 0000000000..8b25d59d2e
--- /dev/null
+++ b/test/css/samples/directive-special-character/expected.css
@@ -0,0 +1 @@
+.foo\:bar.svelte-xyz{color:red}
\ No newline at end of file
diff --git a/test/css/samples/directive-special-character/expected.html b/test/css/samples/directive-special-character/expected.html
new file mode 100644
index 0000000000..40eff4ca21
--- /dev/null
+++ b/test/css/samples/directive-special-character/expected.html
@@ -0,0 +1 @@
+<div class="svelte-xyz foo:bar">Hello world</div>
\ No newline at end of file
diff --git a/test/css/samples/directive-special-character/input.svelte b/test/css/samples/directive-special-character/input.svelte
new file mode 100644
index 0000000000..8f95fe1355
--- /dev/null
+++ b/test/css/samples/directive-special-character/input.svelte
@@ -0,0 +1,11 @@
+<script>
+	const enabled = true;
+</script>
+
+<div class:foo:bar={enabled}>Hello world</div>
+
+<style>
+	.foo\:bar {
+		color: red;
+	}
+</style>
diff --git a/test/store/index.ts b/test/store/index.ts
index d4934f756a..bb999f1220 100644
--- a/test/store/index.ts
+++ b/test/store/index.ts
@@ -189,6 +189,34 @@ describe('store', () => {
 			unsubscribe();
 		});
 
+		it('prevents diamond dependency problem', () => {
+			const count = writable(0);
+			const values = [];
+
+			const a = derived(count, $count => {
+				return 'a' + $count;
+			});
+
+			const b = derived(count, $count => {
+				return 'b' + $count;
+			});
+
+			const combined = derived([a, b], ([a, b]) => {
+				return a + b;
+			});
+
+			const unsubscribe = combined.subscribe(v => {
+				values.push(v);
+			});
+
+			assert.deepEqual(values, ['a0b0']);
+
+			count.set(1);
+			assert.deepEqual(values, ['a0b0', 'a1b1']);
+
+			unsubscribe();
+		});
+
 		it('is updated with safe_not_equal logic', () => {
 			const arr = [0];