diff --git a/site/content/docs/02-template-syntax.md b/site/content/docs/02-template-syntax.md
index a69400f8e3..c6fd5c8b2d 100644
--- a/site/content/docs/02-template-syntax.md
+++ b/site/content/docs/02-template-syntax.md
@@ -7,7 +7,7 @@ title: Template syntax
 
 ---
 
-A lowercase tag, like `<div>`, denotes a regular HTML element. A capitalised tag, such as `<Widget>`, indicates a *component*.
+A lowercase tag, like `<div>`, denotes a regular HTML element. A capitalised tag, such as `<Widget>` or `<Namespace.Widget>`, indicates a *component*.
 
 ```html
 <script>
diff --git a/src/compile/Component.ts b/src/compile/Component.ts
index aad5e98413..dd41a0a645 100644
--- a/src/compile/Component.ts
+++ b/src/compile/Component.ts
@@ -759,7 +759,7 @@ export default class Component {
 					const { name } = object;
 
 					if (name[0] === '$' && !scope.has(name)) {
-						component.warn_if_undefined(object, null);
+						component.warn_if_undefined(name, object, null);
 					}
 				}
 			},
@@ -1202,9 +1202,7 @@ export default class Component {
 		return `ctx.${name}`;
 	}
 
-	warn_if_undefined(node, template_scope: TemplateScope) {
-		let { name } = node;
-
+	warn_if_undefined(name: string, node, template_scope: TemplateScope) {
 		if (name[0] === '$') {
 			name = name.slice(1);
 			this.has_reactive_assignments = true; // TODO does this belong here?
diff --git a/src/compile/nodes/Action.ts b/src/compile/nodes/Action.ts
index feec3fada8..77b9e3c846 100644
--- a/src/compile/nodes/Action.ts
+++ b/src/compile/nodes/Action.ts
@@ -11,7 +11,7 @@ export default class Action extends Node {
 	constructor(component: Component, parent, scope, info) {
 		super(component, parent, scope, info);
 
-		component.warn_if_undefined(info, scope);
+		component.warn_if_undefined(info.name, info, scope);
 
 		this.name = info.name;
 		component.qualify(info.name);
diff --git a/src/compile/nodes/Animation.ts b/src/compile/nodes/Animation.ts
index 638a88b169..6ccdbb0803 100644
--- a/src/compile/nodes/Animation.ts
+++ b/src/compile/nodes/Animation.ts
@@ -10,7 +10,7 @@ export default class Animation extends Node {
 	constructor(component: Component, parent, scope, info) {
 		super(component, parent, scope, info);
 
-		component.warn_if_undefined(info, scope);
+		component.warn_if_undefined(info.name, info, scope);
 
 		this.name = info.name;
 		component.qualify(info.name);
diff --git a/src/compile/nodes/InlineComponent.ts b/src/compile/nodes/InlineComponent.ts
index 0d8801aad1..3359e981ed 100644
--- a/src/compile/nodes/InlineComponent.ts
+++ b/src/compile/nodes/InlineComponent.ts
@@ -23,8 +23,9 @@ export default class InlineComponent extends Node {
 		super(component, parent, scope, info);
 
 		if (info.name !== 'svelte:component' && info.name !== 'svelte:self') {
-			component.warn_if_undefined(info, scope);
-			component.add_reference(info.name);
+			const name = info.name.split('.')[0]; // accommodate namespaces
+			component.warn_if_undefined(name, info, scope);
+			component.add_reference(name);
 		}
 
 		this.name = info.name;
diff --git a/src/compile/nodes/Transition.ts b/src/compile/nodes/Transition.ts
index c3f22d888e..82eb578f0f 100644
--- a/src/compile/nodes/Transition.ts
+++ b/src/compile/nodes/Transition.ts
@@ -12,7 +12,7 @@ export default class Transition extends Node {
 	constructor(component: Component, parent, scope, info) {
 		super(component, parent, scope, info);
 
-		component.warn_if_undefined(info, scope);
+		component.warn_if_undefined(info.name, info, scope);
 
 		this.name = info.name;
 		component.qualify(info.name);
diff --git a/src/compile/nodes/shared/Expression.ts b/src/compile/nodes/shared/Expression.ts
index 22cb403f75..fc188e9673 100644
--- a/src/compile/nodes/shared/Expression.ts
+++ b/src/compile/nodes/shared/Expression.ts
@@ -149,7 +149,7 @@ export default class Expression {
 						}
 
 						component.add_reference(name);
-						component.warn_if_undefined(nodes[0], template_scope);
+						component.warn_if_undefined(name, nodes[0], template_scope);
 					}
 
 					this.skip();
diff --git a/src/compile/render-dom/wrappers/InlineComponent/index.ts b/src/compile/render-dom/wrappers/InlineComponent/index.ts
index c696f4813c..f9d79d2693 100644
--- a/src/compile/render-dom/wrappers/InlineComponent/index.ts
+++ b/src/compile/render-dom/wrappers/InlineComponent/index.ts
@@ -63,7 +63,7 @@ export default class InlineComponentWrapper extends Wrapper {
 		this.var = (
 			this.node.name === 'svelte:self' ? renderer.component.name :
 			this.node.name === 'svelte:component' ? 'switch_instance' :
-			this.node.name
+			sanitize(this.node.name)
 		).toLowerCase();
 
 		if (this.node.children.length) {
diff --git a/test/runtime/index.js b/test/runtime/index.js
index 579dc665c6..64d7f3ae51 100644
--- a/test/runtime/index.js
+++ b/test/runtime/index.js
@@ -75,7 +75,7 @@ describe("runtime", () => {
 			compileOptions.accessors = 'accessors' in config ? config.accessors : true;
 
 			Object.keys(require.cache)
-				.filter(x => x.endsWith(".svelte"))
+				.filter(x => x.endsWith('.svelte'))
 				.forEach(file => {
 					delete require.cache[file];
 				});
diff --git a/test/runtime/samples/component-namespaced/Foo.svelte b/test/runtime/samples/component-namespaced/Foo.svelte
new file mode 100644
index 0000000000..67ab955233
--- /dev/null
+++ b/test/runtime/samples/component-namespaced/Foo.svelte
@@ -0,0 +1,5 @@
+<script>
+	export let foo;
+</script>
+
+<p>foo {foo}</p>
\ No newline at end of file
diff --git a/test/runtime/samples/component-namespaced/_config.js b/test/runtime/samples/component-namespaced/_config.js
new file mode 100644
index 0000000000..b91795d6c8
--- /dev/null
+++ b/test/runtime/samples/component-namespaced/_config.js
@@ -0,0 +1,22 @@
+import * as path from 'path';
+
+export default {
+	props: {
+		a: 1
+	},
+
+	html: `
+		<p>foo 1</p>
+	`,
+
+	before_test() {
+		delete require.cache[path.resolve(__dirname, 'components.js')];
+	},
+
+	test({ assert, component, target }) {
+		component.a = 2;
+		assert.htmlEqual(target.innerHTML, `
+			<p>foo 2</p>
+		`);
+	}
+};
\ No newline at end of file
diff --git a/test/runtime/samples/component-namespaced/components.js b/test/runtime/samples/component-namespaced/components.js
new file mode 100644
index 0000000000..832d2412ee
--- /dev/null
+++ b/test/runtime/samples/component-namespaced/components.js
@@ -0,0 +1,3 @@
+import Foo from './Foo.svelte';
+
+export default { Foo };
\ No newline at end of file
diff --git a/test/runtime/samples/component-namespaced/main.svelte b/test/runtime/samples/component-namespaced/main.svelte
new file mode 100644
index 0000000000..541b68e47e
--- /dev/null
+++ b/test/runtime/samples/component-namespaced/main.svelte
@@ -0,0 +1,7 @@
+<script>
+	import Components from './components.js';
+
+	export let a;
+</script>
+
+<Components.Foo foo={a}/>
\ No newline at end of file
diff --git a/test/server-side-rendering/index.js b/test/server-side-rendering/index.js
index 6a546b0b7b..9f67ee06e9 100644
--- a/test/server-side-rendering/index.js
+++ b/test/server-side-rendering/index.js
@@ -96,10 +96,11 @@ describe("ssr", () => {
 		(config.skip ? it.skip : config.solo ? it.only : it)(dir, () => {
 			const cwd = path.resolve("test/runtime/samples", dir);
 
-			glob('**/*.svelte', { cwd: `test/runtime/samples/${dir}` }).forEach(file => {
-				const resolved = require.resolve(`../runtime/samples/${dir}/${file}`);
-				delete require.cache[resolved];
-			});
+			Object.keys(require.cache)
+				.filter(x => x.endsWith('.svelte'))
+				.forEach(file => {
+					delete require.cache[file];
+				});
 
 			const compileOptions = Object.assign({ sveltePath }, config.compileOptions, {
 				generate: 'ssr'
diff --git a/test/validator/samples/component-namespaced/input.svelte b/test/validator/samples/component-namespaced/input.svelte
new file mode 100644
index 0000000000..996d2d8769
--- /dev/null
+++ b/test/validator/samples/component-namespaced/input.svelte
@@ -0,0 +1,5 @@
+<script>
+	import * as NS from 'some-library';
+</script>
+
+<NS.Foo/>
\ No newline at end of file
diff --git a/test/validator/samples/component-namespaced/warnings.json b/test/validator/samples/component-namespaced/warnings.json
new file mode 100644
index 0000000000..0637a088a0
--- /dev/null
+++ b/test/validator/samples/component-namespaced/warnings.json
@@ -0,0 +1 @@
+[]
\ No newline at end of file
diff --git a/test/vars/samples/component-namespaced/_config.js b/test/vars/samples/component-namespaced/_config.js
new file mode 100644
index 0000000000..ac63873967
--- /dev/null
+++ b/test/vars/samples/component-namespaced/_config.js
@@ -0,0 +1,16 @@
+export default {
+	test(assert, vars) {
+		assert.deepEqual(vars, [
+			{
+				name: 'NS',
+				export_name: null,
+				injected: false,
+				module: false,
+				mutated: false,
+				reassigned: false,
+				referenced: true,
+				writable: false
+			}
+		]);
+	}
+};
\ No newline at end of file
diff --git a/test/vars/samples/component-namespaced/input.svelte b/test/vars/samples/component-namespaced/input.svelte
new file mode 100644
index 0000000000..996d2d8769
--- /dev/null
+++ b/test/vars/samples/component-namespaced/input.svelte
@@ -0,0 +1,5 @@
+<script>
+	import * as NS from 'some-library';
+</script>
+
+<NS.Foo/>
\ No newline at end of file