diff --git a/CHANGELOG.md b/CHANGELOG.md
index c94c24dd65..759aabfd7d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Svelte changelog
 
+## Unreleased
+
+* Fix indirect bindings involving elements with spreads ([#3680](https://github.com/sveltejs/svelte/issues/3680))
+* Warn when using `<Foo/>` and `Foo` is dynamic ([#4331](https://github.com/sveltejs/svelte/issues/4331))
+* Fix unneeded updating of keyed each blocks ([#4373](https://github.com/sveltejs/svelte/issues/4373))
+
 ## 3.18.2
 
 * Fix binding to module-level variables ([#4086](https://github.com/sveltejs/svelte/issues/4086))
diff --git a/site/content/blog/2019-04-16-svelte-for-new-developers.md b/site/content/blog/2019-04-16-svelte-for-new-developers.md
index fc8e993e88..796a6c11ab 100644
--- a/site/content/blog/2019-04-16-svelte-for-new-developers.md
+++ b/site/content/blog/2019-04-16-svelte-for-new-developers.md
@@ -18,7 +18,7 @@ You'll be using the *command line*, also known as the terminal. On Windows, you
 
 The command line is a way to interact with your computer (or another computer! but that's a topic for another time) with more power and control than the GUI (graphical user interface) that most people use day-to-day.
 
-Once on the command line, you can navigate the filesystem using `ls` to list the contents of your current directory, and `cd` to change the current directory. For example, if you had a `Development` directory of your projects inside your home directory, you would type
+Once on the command line, you can navigate the filesystem using `ls` (`dir` on Windows) to list the contents of your current directory, and `cd` to change the current directory. For example, if you had a `Development` directory of your projects inside your home directory, you would type
 
 ```bash
 cd Development
@@ -34,7 +34,7 @@ cd svelte-projects
 A full introduction to the command line is out of the scope of this guide, but here are a few more useful commands:
 
 * `cd ..` — navigates to the parent of the current directory
-* `cat my-file.txt` — on Mac/Linux, lists the contents of `my-file.txt`
+* `cat my-file.txt` — on Mac/Linux (`type my-file.txt` on Windows), lists the contents of `my-file.txt`
 * `open .` (or `start .` on Windows) — opens the current directory in Finder or File Explorer
 
 
diff --git a/site/content/docs/04-compile-time.md b/site/content/docs/04-compile-time.md
index c46cef117d..0cb2ac3caf 100644
--- a/site/content/docs/04-compile-time.md
+++ b/site/content/docs/04-compile-time.md
@@ -185,7 +185,7 @@ const ast = svelte.parse(source, { filename: 'App.svelte' });
 result: {
 	code: string,
 	dependencies: Array<string>
-} = svelte.preprocess(
+} = await svelte.preprocess(
 	source: string,
 	preprocessors: Array<{
 		markup?: (input: { content: string, filename: string }) => Promise<{
@@ -222,7 +222,7 @@ The `markup` function receives the entire component source text, along with the
 ```js
 const svelte = require('svelte/compiler');
 
-const { code } = svelte.preprocess(source, {
+const { code } = await svelte.preprocess(source, {
 	markup: ({ content, filename }) => {
 		return {
 			code: content.replace(/foo/g, 'bar')
@@ -244,7 +244,7 @@ const svelte = require('svelte/compiler');
 const sass = require('node-sass');
 const { dirname } = require('path');
 
-const { code, dependencies } = svelte.preprocess(source, {
+const { code, dependencies } = await svelte.preprocess(source, {
 	style: async ({ content, attributes, filename }) => {
 		// only process <style lang="sass">
 		if (attributes.lang !== 'sass') return;
@@ -277,7 +277,7 @@ Multiple preprocessors can be used together. The output of the first becomes the
 ```js
 const svelte = require('svelte/compiler');
 
-const { code } = svelte.preprocess(source, [
+const { code } = await svelte.preprocess(source, [
 	{
 		markup: () => {
 			console.log('this runs first');
diff --git a/src/compiler/compile/render_dom/wrappers/EachBlock.ts b/src/compiler/compile/render_dom/wrappers/EachBlock.ts
index 8c01cf8e95..1970a98c51 100644
--- a/src/compiler/compile/render_dom/wrappers/EachBlock.ts
+++ b/src/compiler/compile/render_dom/wrappers/EachBlock.ts
@@ -412,16 +412,25 @@ export default class EachBlockWrapper extends Wrapper {
 				? `@outro_and_destroy_block`
 				: `@destroy_block`;
 
-		block.chunks.update.push(b`
-			const ${this.vars.each_block_value} = ${snippet};
+		const all_dependencies = new Set(this.block.dependencies); // TODO should be dynamic deps only
+		this.node.expression.dynamic_dependencies().forEach((dependency: string) => {
+			all_dependencies.add(dependency);
+		});
 
-			${this.block.has_outros && b`@group_outros();`}
-			${this.node.has_animation && b`for (let #i = 0; #i < ${view_length}; #i += 1) ${iterations}[#i].r();`}
-			${this.renderer.options.dev && b`@validate_each_keys(#ctx, ${this.vars.each_block_value}, ${this.vars.get_each_context}, ${get_key});`}
-			${iterations} = @update_keyed_each(${iterations}, #dirty, ${get_key}, ${dynamic ? 1 : 0}, #ctx, ${this.vars.each_block_value}, ${lookup}, ${update_mount_node}, ${destroy}, ${create_each_block}, ${update_anchor_node}, ${this.vars.get_each_context});
-			${this.node.has_animation && b`for (let #i = 0; #i < ${view_length}; #i += 1) ${iterations}[#i].a();`}
-			${this.block.has_outros && b`@check_outros();`}
-		`);
+		if (all_dependencies.size) {
+			block.chunks.update.push(b`
+				if (${block.renderer.dirty(Array.from(all_dependencies))}) {
+					const ${this.vars.each_block_value} = ${snippet};
+
+					${this.block.has_outros && b`@group_outros();`}
+					${this.node.has_animation && b`for (let #i = 0; #i < ${view_length}; #i += 1) ${iterations}[#i].r();`}
+					${this.renderer.options.dev && b`@validate_each_keys(#ctx, ${this.vars.each_block_value}, ${this.vars.get_each_context}, ${get_key});`}
+					${iterations} = @update_keyed_each(${iterations}, #dirty, ${get_key}, ${dynamic ? 1 : 0}, #ctx, ${this.vars.each_block_value}, ${lookup}, ${update_mount_node}, ${destroy}, ${create_each_block}, ${update_anchor_node}, ${this.vars.get_each_context});
+					${this.node.has_animation && b`for (let #i = 0; #i < ${view_length}; #i += 1) ${iterations}[#i].a();`}
+					${this.block.has_outros && b`@check_outros();`}
+				}
+			`);
+		}
 
 		if (this.block.has_outros) {
 			block.chunks.outro.push(b`
diff --git a/src/compiler/compile/render_dom/wrappers/Element/Attribute.ts b/src/compiler/compile/render_dom/wrappers/Element/Attribute.ts
index ecddaaebaa..85f252f57e 100644
--- a/src/compiler/compile/render_dom/wrappers/Element/Attribute.ts
+++ b/src/compiler/compile/render_dom/wrappers/Element/Attribute.ts
@@ -39,20 +39,25 @@ export default class AttributeWrapper {
 		}
 	}
 
-	render(block: Block) {
+	is_indirectly_bound_value() {
 		const element = this.parent;
 		const name = fix_attribute_casing(this.node.name);
-
-		const metadata = this.get_metadata();
-
-		const is_indirectly_bound_value =
-			name === 'value' &&
+		return name === 'value' &&
 			(element.node.name === 'option' || // TODO check it's actually bound
 				(element.node.name === 'input' &&
-					element.node.bindings.find(
+					element.node.bindings.some(
 						(binding) =>
 							/checked|group/.test(binding.name)
 					)));
+	}
+
+	render(block: Block) {
+		const element = this.parent;
+		const name = fix_attribute_casing(this.node.name);
+
+		const metadata = this.get_metadata();
+
+		const is_indirectly_bound_value = this.is_indirectly_bound_value();
 
 		const property_name = is_indirectly_bound_value
 			? '__value'
diff --git a/src/compiler/compile/render_dom/wrappers/Element/index.ts b/src/compiler/compile/render_dom/wrappers/Element/index.ts
index 3882dd2971..c9f51a0aaf 100644
--- a/src/compiler/compile/render_dom/wrappers/Element/index.ts
+++ b/src/compiler/compile/render_dom/wrappers/Element/index.ts
@@ -675,10 +675,10 @@ export default class ElementWrapper extends Wrapper {
 					updates.push(condition ? x`${condition} && ${snippet}` : snippet);
 				} else {
 					const metadata = attr.get_metadata();
-					const snippet = x`{ ${
-						(metadata && metadata.property_name) ||
-						fix_attribute_casing(attr.node.name)
-					}: ${attr.get_value(block)} }`;
+					const name = attr.is_indirectly_bound_value()
+						? '__value'
+						: (metadata && metadata.property_name) || fix_attribute_casing(attr.node.name);
+					const snippet = x`{ ${name}: ${attr.get_value(block)} }`;
 					initial_props.push(snippet);
 
 					updates.push(condition ? x`${condition} && ${snippet}` : snippet);
diff --git a/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts b/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
index 631c172576..f1c57ed094 100644
--- a/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
+++ b/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
@@ -106,11 +106,28 @@ export default class InlineComponentWrapper extends Wrapper {
 		block.add_outro();
 	}
 
+	warn_if_reactive() {
+		const { name } = this.node;
+		const variable = this.renderer.component.var_lookup.get(name);
+		if (!variable) {
+			return;
+		}
+
+		if (variable.reassigned || variable.export_name || variable.is_reactive_dependency) {
+			this.renderer.component.warn(this.node, {
+				code: 'reactive-component',
+				message: `<${name}/> will not be reactive if ${name} changes. Use <svelte:component this={${name}}/> if you want this reactivity.`,
+			});
+		}
+	}
+
 	render(
 		block: Block,
 		parent_node: Identifier,
 		parent_nodes: Identifier
 	) {
+		this.warn_if_reactive();
+
 		const { renderer } = this;
 		const { component } = renderer;
 
diff --git a/src/runtime/internal/dom.ts b/src/runtime/internal/dom.ts
index a3ab80db4b..4cf445aecd 100644
--- a/src/runtime/internal/dom.ts
+++ b/src/runtime/internal/dom.ts
@@ -108,7 +108,7 @@ export function set_attributes(node: Element & ElementCSSInlineStyle, attributes
 			node.removeAttribute(key);
 		} else if (key === 'style') {
 			node.style.cssText = attributes[key];
-		} else if (descriptors[key] && descriptors[key].set) {
+		} else if (key === '__value' || descriptors[key] && descriptors[key].set) {
 			node[key] = attributes[key];
 		} else {
 			attr(node, key, attributes[key]);
diff --git a/test/js/samples/each-block-keyed-animated/expected.js b/test/js/samples/each-block-keyed-animated/expected.js
index 3b697d6860..7fb81c27a2 100644
--- a/test/js/samples/each-block-keyed-animated/expected.js
+++ b/test/js/samples/each-block-keyed-animated/expected.js
@@ -92,10 +92,12 @@ function create_fragment(ctx) {
 			insert(target, each_1_anchor, anchor);
 		},
 		p(ctx, [dirty]) {
-			const each_value = /*things*/ ctx[0];
-			for (let i = 0; i < each_blocks.length; i += 1) each_blocks[i].r();
-			each_blocks = update_keyed_each(each_blocks, dirty, get_key, 1, ctx, each_value, each_1_lookup, each_1_anchor.parentNode, fix_and_destroy_block, create_each_block, each_1_anchor, get_each_context);
-			for (let i = 0; i < each_blocks.length; i += 1) each_blocks[i].a();
+			if (dirty & /*things*/ 1) {
+				const each_value = /*things*/ ctx[0];
+				for (let i = 0; i < each_blocks.length; i += 1) each_blocks[i].r();
+				each_blocks = update_keyed_each(each_blocks, dirty, get_key, 1, ctx, each_value, each_1_lookup, each_1_anchor.parentNode, fix_and_destroy_block, create_each_block, each_1_anchor, get_each_context);
+				for (let i = 0; i < each_blocks.length; i += 1) each_blocks[i].a();
+			}
 		},
 		i: noop,
 		o: noop,
diff --git a/test/js/samples/each-block-keyed/expected.js b/test/js/samples/each-block-keyed/expected.js
index 1cd9a31ece..ad8c074e99 100644
--- a/test/js/samples/each-block-keyed/expected.js
+++ b/test/js/samples/each-block-keyed/expected.js
@@ -77,8 +77,10 @@ function create_fragment(ctx) {
 			insert(target, each_1_anchor, anchor);
 		},
 		p(ctx, [dirty]) {
-			const each_value = /*things*/ ctx[0];
-			each_blocks = update_keyed_each(each_blocks, dirty, get_key, 1, ctx, each_value, each_1_lookup, each_1_anchor.parentNode, destroy_block, create_each_block, each_1_anchor, get_each_context);
+			if (dirty & /*things*/ 1) {
+				const each_value = /*things*/ ctx[0];
+				each_blocks = update_keyed_each(each_blocks, dirty, get_key, 1, ctx, each_value, each_1_lookup, each_1_anchor.parentNode, destroy_block, create_each_block, each_1_anchor, get_each_context);
+			}
 		},
 		i: noop,
 		o: noop,
diff --git a/test/runtime/samples/binding-indirect-spread/_config.js b/test/runtime/samples/binding-indirect-spread/_config.js
new file mode 100644
index 0000000000..1f24fcdbcb
--- /dev/null
+++ b/test/runtime/samples/binding-indirect-spread/_config.js
@@ -0,0 +1,44 @@
+export default {
+	skip_if_ssr: true,
+	async test({ assert, component, target, window }) {
+		const event = new window.MouseEvent('click');
+
+		const [radio1, radio2, radio3] = target.querySelectorAll('input[type=radio]');
+
+		assert.ok(!radio1.checked);
+		assert.ok(radio2.checked);
+		assert.ok(!radio3.checked);
+
+		component.radio = 'radio1';
+
+		assert.ok(radio1.checked);
+		assert.ok(!radio2.checked);
+		assert.ok(!radio3.checked);
+
+		await radio3.dispatchEvent(event);
+
+		assert.equal(component.radio, 'radio3');
+		assert.ok(!radio1.checked);
+		assert.ok(!radio2.checked);
+		assert.ok(radio3.checked);
+
+		const [check1, check2, check3] = target.querySelectorAll('input[type=checkbox]');
+
+		assert.ok(!check1.checked);
+		assert.ok(check2.checked);
+		assert.ok(!check3.checked);
+
+		component.check = ['check1', 'check2'];
+
+		assert.ok(check1.checked);
+		assert.ok(check2.checked);
+		assert.ok(!check3.checked);
+
+		await check3.dispatchEvent(event);
+
+		assert.deepEqual(component.check, ['check1', 'check2', 'check3']);
+		assert.ok(check1.checked);
+		assert.ok(check2.checked);
+		assert.ok(check3.checked);
+	}
+};
diff --git a/test/runtime/samples/binding-indirect-spread/main.svelte b/test/runtime/samples/binding-indirect-spread/main.svelte
new file mode 100644
index 0000000000..43129b08b7
--- /dev/null
+++ b/test/runtime/samples/binding-indirect-spread/main.svelte
@@ -0,0 +1,12 @@
+<script>
+	export let radio = 'radio2';
+	export let check = ['check2'];
+</script>
+
+<input type='radio' bind:group={radio} value='radio1' {...{}}>
+<input type='radio' bind:group={radio} value='radio2' {...{}}>
+<input type='radio' bind:group={radio} value='radio3' {...{}}>
+
+<input type='checkbox' bind:group={check} value='check1' {...{}}>
+<input type='checkbox' bind:group={check} value='check2' {...{}}>
+<input type='checkbox' bind:group={check} value='check3' {...{}}>
diff --git a/test/runtime/samples/component-binding-blowback-c/main.svelte b/test/runtime/samples/component-binding-blowback-c/main.svelte
index 4876af13a8..75552bf358 100644
--- a/test/runtime/samples/component-binding-blowback-c/main.svelte
+++ b/test/runtime/samples/component-binding-blowback-c/main.svelte
@@ -4,7 +4,7 @@
 	export let count;
 	export let idToValue = Object.create(null);
 
-	function ids() {
+	function ids(count) {
 		return new Array(count)
 			.fill(null)
 			.map((_, i) => ({ id: 'id-' + i}))
@@ -15,7 +15,7 @@
 <input type='number' bind:value={count}>
 
 <ol>
-	{#each ids() as object (object.id)}
+	{#each ids(count) as object (object.id)}
 		<Nested bind:value={idToValue[object.id]} id={object.id}>
 			{object.id}: value is {idToValue[object.id]}
 		</Nested>
diff --git a/test/runtime/samples/each-block-keyed-dynamic-2/_config.js b/test/runtime/samples/each-block-keyed-dynamic-2/_config.js
new file mode 100644
index 0000000000..7eba75a5ff
--- /dev/null
+++ b/test/runtime/samples/each-block-keyed-dynamic-2/_config.js
@@ -0,0 +1,23 @@
+export default {
+	html: `
+	<button>Click Me</button>
+	0
+	<ul></ul>
+	`,
+
+	async test({ assert, component, target, window }) {
+		const button = target.querySelector("button");
+
+		const event = new window.MouseEvent("click");
+		await button.dispatchEvent(event);
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+			<button>Click Me</button>
+			1
+			<ul></ul>
+		`
+		);
+	}
+};
diff --git a/test/runtime/samples/each-block-keyed-dynamic-2/main.svelte b/test/runtime/samples/each-block-keyed-dynamic-2/main.svelte
new file mode 100644
index 0000000000..ab455a585e
--- /dev/null
+++ b/test/runtime/samples/each-block-keyed-dynamic-2/main.svelte
@@ -0,0 +1,20 @@
+<script>
+	let num = 0;
+	let cards = [];
+	
+	function click() {
+		// updating cards via push should have no effect to the ul,
+		// since its being mutated instead of reassigned
+		cards.push(num++);
+	}
+</script>
+<button on:click={click}>
+	Click Me
+</button>
+
+{num}
+<ul>
+	{#each cards as c, i (i)}
+		<li>{c}</li>
+  {/each}
+</ul>
diff --git a/test/validator/index.js b/test/validator/index.js
index 8bf0400d7c..9bce5e149b 100644
--- a/test/validator/index.js
+++ b/test/validator/index.js
@@ -20,6 +20,7 @@ describe("validate", () => {
 			const input = fs.readFileSync(`${__dirname}/samples/${dir}/input.svelte`, "utf-8").replace(/\s+$/, "");
 			const expected_warnings = tryToLoadJson(`${__dirname}/samples/${dir}/warnings.json`) || [];
 			const expected_errors = tryToLoadJson(`${__dirname}/samples/${dir}/errors.json`);
+			const options = tryToLoadJson(`${__dirname}/samples/${dir}/options.json`);
 
 			let error;
 
@@ -28,7 +29,8 @@ describe("validate", () => {
 					dev: config.dev,
 					legacy: config.legacy,
 					generate: false,
-					customElement: config.customElement
+					customElement: config.customElement,
+					...options,
 				});
 
 				assert.deepEqual(warnings.map(w => ({
diff --git a/test/validator/samples/component-dynamic/input.svelte b/test/validator/samples/component-dynamic/input.svelte
new file mode 100644
index 0000000000..f591a84fe1
--- /dev/null
+++ b/test/validator/samples/component-dynamic/input.svelte
@@ -0,0 +1,18 @@
+<script>
+	import A from './A.svelte';
+	import B from './B.svelte';
+
+	let Let = A;
+	function update() {
+		Let = B;
+	}
+
+	export let ExportLet = B;
+
+	$: Reactive = random() ? A : B;
+</script>
+
+<Let />
+<ExportLet />
+<Reactive />
+<svelte:component this={Let} />
\ No newline at end of file
diff --git a/test/validator/samples/component-dynamic/options.json b/test/validator/samples/component-dynamic/options.json
new file mode 100644
index 0000000000..3a50892eba
--- /dev/null
+++ b/test/validator/samples/component-dynamic/options.json
@@ -0,0 +1,3 @@
+{
+  "generate": true
+}
\ No newline at end of file
diff --git a/test/validator/samples/component-dynamic/warnings.json b/test/validator/samples/component-dynamic/warnings.json
new file mode 100644
index 0000000000..457ef11a1e
--- /dev/null
+++ b/test/validator/samples/component-dynamic/warnings.json
@@ -0,0 +1,47 @@
+[
+	{
+		"code": "reactive-component",
+    "message": "<Let/> will not be reactive if Let changes. Use <svelte:component this={Let}/> if you want this reactivity.",
+    "pos": 190,
+		"end": {
+			"character": 197,
+			"column": 7,
+			"line": 15
+		},
+		"start": {
+			"character": 190,
+			"column": 0,
+			"line": 15
+		}
+	},
+	{
+    "message": "<ExportLet/> will not be reactive if ExportLet changes. Use <svelte:component this={ExportLet}/> if you want this reactivity.",
+		"code": "reactive-component",
+    "pos": 198,
+		"end": {
+			"character": 211,
+			"column": 13,
+			"line": 16
+		},
+		"start": {
+			"character": 198,
+			"column": 0,
+			"line": 16
+		}
+	},
+	{
+    "message": "<Reactive/> will not be reactive if Reactive changes. Use <svelte:component this={Reactive}/> if you want this reactivity.",
+		"code": "reactive-component",
+    "pos": 212,
+		"end": {
+			"character": 224,
+			"column": 12,
+			"line": 17
+		},
+		"start": {
+			"character": 212,
+			"column": 0,
+			"line": 17
+		}
+	}
+]