diff --git a/src/compile/nodes/CatchBlock.ts b/src/compile/nodes/CatchBlock.ts
index 6486f4a3a8..db202b9517 100644
--- a/src/compile/nodes/CatchBlock.ts
+++ b/src/compile/nodes/CatchBlock.ts
@@ -12,7 +12,7 @@ export default class CatchBlock extends Node {
 		super(component, parent, scope, info);
 
 		this.scope = scope.child();
-		this.scope.add(parent.error, parent.expression.dependencies);
+		this.scope.add(parent.error, parent.expression.dependencies, this);
 		this.children = mapChildren(component, parent, this.scope, info.children);
 
 		this.warnIfEmptyBlock();
diff --git a/src/compile/nodes/EachBlock.ts b/src/compile/nodes/EachBlock.ts
index 6770ab8739..5ea1d5e033 100644
--- a/src/compile/nodes/EachBlock.ts
+++ b/src/compile/nodes/EachBlock.ts
@@ -20,6 +20,7 @@ export default class EachBlock extends Node {
 	scope: TemplateScope;
 	contexts: Array<{ name: string, tail: string }>;
 	hasAnimation: boolean;
+	has_binding = false;
 
 	children: Node[];
 	else?: ElseBlock;
@@ -38,7 +39,7 @@ export default class EachBlock extends Node {
 		unpackDestructuring(this.contexts, info.context, '');
 
 		this.contexts.forEach(context => {
-			this.scope.add(context.key.name, this.expression.dependencies);
+			this.scope.add(context.key.name, this.expression.dependencies, this);
 		});
 
 		this.key = info.key
@@ -48,7 +49,7 @@ export default class EachBlock extends Node {
 		if (this.index) {
 			// index can only change if this is a keyed each block
 			const dependencies = this.key ? this.expression.dependencies : [];
-			this.scope.add(this.index, dependencies);
+			this.scope.add(this.index, dependencies, this);
 		}
 
 		this.hasAnimation = false;
diff --git a/src/compile/nodes/InlineComponent.ts b/src/compile/nodes/InlineComponent.ts
index 8a075d0ce9..4d3b7332a6 100644
--- a/src/compile/nodes/InlineComponent.ts
+++ b/src/compile/nodes/InlineComponent.ts
@@ -82,7 +82,7 @@ export default class InlineComponent extends Node {
 				const dependencies = new Set([l.name]);
 
 				l.names.forEach(name => {
-					this.scope.add(name, dependencies);
+					this.scope.add(name, dependencies, this);
 				});
 			});
 		} else {
diff --git a/src/compile/nodes/ThenBlock.ts b/src/compile/nodes/ThenBlock.ts
index 9921eb77c7..6df8259273 100644
--- a/src/compile/nodes/ThenBlock.ts
+++ b/src/compile/nodes/ThenBlock.ts
@@ -12,7 +12,7 @@ export default class ThenBlock extends Node {
 		super(component, parent, scope, info);
 
 		this.scope = scope.child();
-		this.scope.add(parent.value, parent.expression.dependencies);
+		this.scope.add(parent.value, parent.expression.dependencies, this);
 		this.children = mapChildren(component, parent, this.scope, info.children);
 
 		this.warnIfEmptyBlock();
diff --git a/src/compile/nodes/shared/Expression.ts b/src/compile/nodes/shared/Expression.ts
index 852065d98d..9ec0c92e84 100644
--- a/src/compile/nodes/shared/Expression.ts
+++ b/src/compile/nodes/shared/Expression.ts
@@ -113,7 +113,10 @@ export default class Expression {
 				// function, and it only applies if the dependency is writable
 				// or a sub-path of a non-writable
 				if (component.instance_script) {
-					if (component.writable_declarations.has(name) || name[0] === '$' || (component.userVars.has(name) && deep)) {
+					const owner = template_scope.getOwner(name);
+					const is_let = owner && (owner.type === 'InlineComponent' || owner.type === 'Element');
+
+					if (is_let || component.writable_declarations.has(name) || name[0] === '$' || (component.userVars.has(name) && deep)) {
 						dynamic_dependencies.add(name);
 					}
 				} else {
diff --git a/src/compile/nodes/shared/TemplateScope.ts b/src/compile/nodes/shared/TemplateScope.ts
index 8d31e848e6..df48cc57f9 100644
--- a/src/compile/nodes/shared/TemplateScope.ts
+++ b/src/compile/nodes/shared/TemplateScope.ts
@@ -1,19 +1,28 @@
+import Node from './Node';
+import EachBlock from '../EachBlock';
+import ThenBlock from '../ThenBlock';
+import CatchBlock from '../CatchBlock';
+import InlineComponent from '../InlineComponent';
+
+type NodeWithScope = EachBlock | ThenBlock | CatchBlock | InlineComponent | Element;
+
 export default class TemplateScope {
 	names: Set<string>;
 	dependenciesForName: Map<string, Set<string>>;
-	mutables: Set<string>;
+	mutables: Set<string> = new Set();
+	owners: Map<string, NodeWithScope> = new Map();
 	parent?: TemplateScope;
 
 	constructor(parent?: TemplateScope) {
 		this.parent = parent;
 		this.names = new Set(parent ? parent.names : []);
 		this.dependenciesForName = new Map(parent ? parent.dependenciesForName : []);
-		this.mutables = new Set();
 	}
 
-	add(name, dependencies: Set<string>) {
+	add(name, dependencies: Set<string>, owner) {
 		this.names.add(name);
 		this.dependenciesForName.set(name, dependencies);
+		this.owners.set(name, owner);
 		return this;
 	}
 
@@ -32,6 +41,10 @@ export default class TemplateScope {
 
 	containsMutable(names: Iterable<string>) {
 		for (const name of names) {
+			const owner = this.getOwner(name);
+			const is_let = owner && (owner.type === 'InlineComponent' || owner.type === 'Element');
+			if (is_let) return true;
+
 			if (name[0] === '$') return true;
 			if (this.mutables.has(name)) return true;
 			else if (this.dependenciesForName.has(name) && this.containsMutable(this.dependenciesForName.get(name))) return true;
@@ -44,4 +57,8 @@ export default class TemplateScope {
 	isTopLevel(name: string) {
 		return !this.parent || !this.names.has(name) && this.parent.isTopLevel(name);
 	}
+
+	getOwner(name: string): NodeWithScope {
+		return this.owners.get(name) || (this.parent && this.parent.getOwner(name));
+	}
 }
\ No newline at end of file
diff --git a/src/compile/render-dom/Block.ts b/src/compile/render-dom/Block.ts
index 299ba637c5..bf4823f863 100644
--- a/src/compile/render-dom/Block.ts
+++ b/src/compile/render-dom/Block.ts
@@ -1,9 +1,10 @@
 import CodeBuilder from '../../utils/CodeBuilder';
 import deindent from '../../utils/deindent';
-import { escape } from '../../utils/stringify';
 import Renderer from './Renderer';
 import Wrapper from './wrappers/shared/Wrapper';
 import EachBlockWrapper from './wrappers/EachBlock';
+import InlineComponentWrapper from './wrappers/InlineComponent';
+import ElementWrapper from './wrappers/Element';
 
 export interface BlockOptions {
 	parent?: Block;
@@ -12,7 +13,6 @@ export interface BlockOptions {
 	comment?: string;
 	key?: string;
 	bindings?: Map<string, () => { object: string, property: string, snippet: string }>;
-	contextOwners?: Map<string, EachBlockWrapper>;
 	dependencies?: Set<string>;
 }
 
@@ -30,7 +30,6 @@ export default class Block {
 	dependencies: Set<string>;
 
 	bindings: Map<string, { object: string, property: string, snippet: string }>;
-	contextOwners: Map<string, EachBlockWrapper>;
 
 	builders: {
 		init: CodeBuilder;
@@ -79,7 +78,6 @@ export default class Block {
 		this.dependencies = new Set();
 
 		this.bindings = options.bindings;
-		this.contextOwners = options.contextOwners;
 
 		this.builders = {
 			init: new CodeBuilder(),
diff --git a/src/compile/render-dom/Renderer.ts b/src/compile/render-dom/Renderer.ts
index 28a8a90dfb..d2bbcb3f53 100644
--- a/src/compile/render-dom/Renderer.ts
+++ b/src/compile/render-dom/Renderer.ts
@@ -44,7 +44,6 @@ export default class Renderer {
 			key: null,
 
 			bindings: new Map(),
-			contextOwners: new Map(),
 
 			dependencies: new Set(),
 		});
diff --git a/src/compile/render-dom/wrappers/EachBlock.ts b/src/compile/render-dom/wrappers/EachBlock.ts
index 490b0929a1..b2741bfe3a 100644
--- a/src/compile/render-dom/wrappers/EachBlock.ts
+++ b/src/compile/render-dom/wrappers/EachBlock.ts
@@ -62,7 +62,6 @@ export default class EachBlockWrapper extends Wrapper {
 	indexName: string;
 
 	var = 'each';
-	hasBinding = false;
 
 	constructor(
 		renderer: Renderer,
@@ -83,8 +82,7 @@ export default class EachBlockWrapper extends Wrapper {
 			name: renderer.component.getUniqueName('create_each_block'),
 			key: <string>node.key, // TODO...
 
-			bindings: new Map(block.bindings),
-			contextOwners: new Map(block.contextOwners)
+			bindings: new Map(block.bindings)
 		});
 
 		// TODO this seems messy
@@ -110,8 +108,6 @@ export default class EachBlockWrapper extends Wrapper {
 		};
 
 		node.contexts.forEach(prop => {
-			this.block.contextOwners.set(prop.key.name, this);
-
 			this.block.bindings.set(prop.key.name, {
 				object: this.vars.each_block_value,
 				property: this.indexName,
@@ -167,8 +163,8 @@ export default class EachBlockWrapper extends Wrapper {
 
 		this.contextProps = this.node.contexts.map(prop => `child_ctx.${prop.key.name} = list[i]${prop.tail};`);
 
-		if (this.hasBinding) this.contextProps.push(`child_ctx.${this.vars.each_block_value} = list;`);
-		if (this.hasBinding || this.node.index) this.contextProps.push(`child_ctx.${this.indexName} = i;`);
+		if (this.node.has_binding) this.contextProps.push(`child_ctx.${this.vars.each_block_value} = list;`);
+		if (this.node.has_binding || this.node.index) this.contextProps.push(`child_ctx.${this.indexName} = i;`);
 
 		const snippet = this.node.expression.render(block);
 
diff --git a/src/compile/render-dom/wrappers/Element/Binding.ts b/src/compile/render-dom/wrappers/Element/Binding.ts
index 7fd65c2e07..cec3283322 100644
--- a/src/compile/render-dom/wrappers/Element/Binding.ts
+++ b/src/compile/render-dom/wrappers/Element/Binding.ts
@@ -7,6 +7,7 @@ import Node from '../../../nodes/shared/Node';
 import Renderer from '../../Renderer';
 import flattenReference from '../../../../utils/flattenReference';
 import { get_tail } from '../../../../utils/get_tail_snippet';
+import EachBlock from '../../../nodes/EachBlock';
 
 // TODO this should live in a specific binding
 const readOnlyMediaAttributes = new Set([
@@ -52,9 +53,9 @@ export default class BindingWrapper {
 			// we need to ensure that the each block creates a context including
 			// the list and the index, if they're not otherwise referenced
 			const { name } = getObject(this.node.expression.node);
-			const eachBlock = block.contextOwners.get(name);
+			const eachBlock = this.parent.node.scope.getOwner(name);
 
-			eachBlock.hasBinding = true;
+			(<EachBlock>eachBlock).has_binding = true;
 		}
 
 		this.object = getObject(this.node.expression.node).name;
diff --git a/src/compile/render-dom/wrappers/Element/index.ts b/src/compile/render-dom/wrappers/Element/index.ts
index 0345026fe6..21b0053fb5 100644
--- a/src/compile/render-dom/wrappers/Element/index.ts
+++ b/src/compile/render-dom/wrappers/Element/index.ts
@@ -21,6 +21,7 @@ import addEventHandlers from '../shared/addEventHandlers';
 import addActions from '../shared/addActions';
 import createDebuggingComment from '../../../../utils/createDebuggingComment';
 import sanitize from '../../../../utils/sanitize';
+import { get_context_merger } from '../shared/get_context_merger';
 
 const events = [
 	{
@@ -136,7 +137,7 @@ export default class ElementWrapper extends Wrapper {
 							name: this.renderer.component.getUniqueName(`create_${sanitize(name)}_slot`)
 						});
 
-						const fn = `({ thing }) => ({ thing })`;
+						const fn = get_context_merger(this.node.lets);
 
 						(<InlineComponentWrapper>owner).slots.set(name, {
 							block: child_block,
diff --git a/src/compile/render-dom/wrappers/Fragment.ts b/src/compile/render-dom/wrappers/Fragment.ts
index aad4c74c80..fcefae9ebb 100644
--- a/src/compile/render-dom/wrappers/Fragment.ts
+++ b/src/compile/render-dom/wrappers/Fragment.ts
@@ -63,6 +63,10 @@ export default class FragmentWrapper {
 		while (i--) {
 			const child = nodes[i];
 
+			if (!child.type) {
+				throw new Error(`missing type`)
+			}
+
 			if (!(child.type in wrappers)) {
 				throw new Error(`TODO implement ${child.type}`);
 			}
diff --git a/src/compile/render-dom/wrappers/InlineComponent/index.ts b/src/compile/render-dom/wrappers/InlineComponent/index.ts
index 643dba89fb..42b962c0bd 100644
--- a/src/compile/render-dom/wrappers/InlineComponent/index.ts
+++ b/src/compile/render-dom/wrappers/InlineComponent/index.ts
@@ -14,6 +14,7 @@ import flattenReference from '../../../../utils/flattenReference';
 import createDebuggingComment from '../../../../utils/createDebuggingComment';
 import sanitize from '../../../../utils/sanitize';
 import { get_context_merger } from '../shared/get_context_merger';
+import EachBlock from '../../../nodes/EachBlock';
 
 export default class InlineComponentWrapper extends Wrapper {
 	var: string;
@@ -46,9 +47,9 @@ export default class InlineComponentWrapper extends Wrapper {
 				// we need to ensure that the each block creates a context including
 				// the list and the index, if they're not otherwise referenced
 				const { name } = getObject(binding.expression.node);
-				const eachBlock = block.contextOwners.get(name);
+				const eachBlock = this.node.scope.getOwner(name);
 
-				eachBlock.hasBinding = true;
+				(<EachBlock>eachBlock).has_binding = true;
 			}
 
 			block.addDependencies(binding.expression.dynamic_dependencies);
@@ -71,6 +72,7 @@ export default class InlineComponentWrapper extends Wrapper {
 				comment: createDebuggingComment(node, renderer.component),
 				name: renderer.component.getUniqueName(`create_default_slot`)
 			});
+
 			this.renderer.blocks.push(default_slot);
 
 			const fn = get_context_merger(this.node.lets);
diff --git a/src/compile/render-dom/wrappers/Slot.ts b/src/compile/render-dom/wrappers/Slot.ts
index e8be2caead..42b028af01 100644
--- a/src/compile/render-dom/wrappers/Slot.ts
+++ b/src/compile/render-dom/wrappers/Slot.ts
@@ -2,16 +2,17 @@ import Wrapper from './shared/Wrapper';
 import Renderer from '../Renderer';
 import Block from '../Block';
 import Slot from '../../nodes/Slot';
-import { quotePropIfNecessary } from '../../../utils/quoteIfNecessary';
 import FragmentWrapper from './Fragment';
 import deindent from '../../../utils/deindent';
 import sanitize from '../../../utils/sanitize';
+import addToSet from '../../../utils/addToSet';
 
 export default class SlotWrapper extends Wrapper {
 	node: Slot;
 	fragment: FragmentWrapper;
 
 	var = 'slot';
+	dependencies: Set<string> = new Set(['$$scope']);
 
 	constructor(
 		renderer: Renderer,
@@ -33,7 +34,11 @@ export default class SlotWrapper extends Wrapper {
 			nextSibling
 		);
 
-		block.addDependencies(new Set(['$$scope']));
+		this.node.attributes.forEach(attribute => {
+			addToSet(this.dependencies, attribute.dependencies);
+		});
+
+		block.addDependencies(this.dependencies);
 	}
 
 	render(
@@ -90,9 +95,14 @@ export default class SlotWrapper extends Wrapper {
 			}
 		`);
 
-		block.builders.update.addLine(
-			`if (${slot} && changed.$$scope) ${slot}.p(ctx.$$scope.changed, ctx.$$scope.ctx);`
-		);
+		let update_conditions = [...this.dependencies].map(name => `changed.${name}`).join(' || ');
+		if (this.dependencies.size > 1) update_conditions = `(${update_conditions})`;
+
+		block.builders.update.addBlock(deindent`
+			if (${slot} && ${update_conditions}) {
+				${slot}.p(@assign(@assign({}, changed), ctx.$$scope.changed), @get_slot_context(ctx.$$slot_${sanitize(slot_name)}, ctx));
+			}
+		`);
 
 		block.builders.destroy.addLine(
 			`if (${slot}) ${slot}.d(detach);`
diff --git a/src/internal/utils.js b/src/internal/utils.js
index 4f6d94ec5e..1ce5f10cd3 100644
--- a/src/internal/utils.js
+++ b/src/internal/utils.js
@@ -49,10 +49,14 @@ export function validate_store(store, name) {
 
 export function create_slot(definition, ctx) {
 	if (definition) {
-		const slot_ctx = definition[1]
-			? assign({}, assign(ctx.$$scope.ctx, definition[1](ctx)))
-			: ctx.$$scope.ctx;
-
+		const slot_ctx = get_slot_context(definition, ctx);
 		return definition[0](slot_ctx);
 	}
-}
\ No newline at end of file
+}
+
+export function get_slot_context(definition, ctx) {
+	return definition[1]
+		? assign({}, assign(ctx.$$scope.ctx, definition[1](ctx)))
+		: ctx.$$scope.ctx
+}
+