diff --git a/packages/compiler-cli/test/compliance/r3_compiler_compliance_spec.ts b/packages/compiler-cli/test/compliance/r3_compiler_compliance_spec.ts
index c0d2e29892..d16705e225 100644
--- a/packages/compiler-cli/test/compliance/r3_compiler_compliance_spec.ts
+++ b/packages/compiler-cli/test/compliance/r3_compiler_compliance_spec.ts
@@ -675,6 +675,35 @@ describe('compiler compliance', () => {
       expectEmit(source, OtherDirectiveFactory, 'Incorrect OtherDirective.ɵfac');
     });
 
+    it('should convert #my-app selector to ["", "id", "my-app"]', () => {
+      const files = {
+        app: {
+          'spec.ts': `
+            import {Component, NgModule} from '@angular/core';
+
+            @Component({selector: '#my-app', template: ''})
+            export class SomeComponent {}
+
+            @NgModule({declarations: [SomeComponent]})
+            export class MyModule{}
+          `
+        }
+      };
+
+      // SomeDirective definition should be:
+      const SomeDirectiveDefinition = `
+        SomeComponent.ɵcmp = $r3$.ɵɵdefineComponent({
+          type: SomeComponent,
+          selectors: [["", "id", "my-app"]],
+          …
+        });
+      `;
+
+      const result = compile(files, angularFiles);
+      const source = result.source;
+
+      expectEmit(source, SomeDirectiveDefinition, 'Incorrect SomeComponent.ɵcomp');
+    });
     it('should support components without selector', () => {
       const files = {
         app: {
diff --git a/packages/compiler/src/selector.ts b/packages/compiler/src/selector.ts
index aacd1d9d29..b5e131de5d 100644
--- a/packages/compiler/src/selector.ts
+++ b/packages/compiler/src/selector.ts
@@ -9,17 +9,31 @@
 import {getHtmlTagDefinition} from './ml_parser/html_tags';
 
 const _SELECTOR_REGEXP = new RegExp(
-    '(\\:not\\()|' +           //":not("
-        '([-\\w]+)|' +         // "tag"
-        '(?:\\.([-\\w]+))|' +  // ".class"
+    '(\\:not\\()|' +               // 1: ":not("
+        '(([\\.\\#]?)[-\\w]+)|' +  // 2: "tag"; 3: "."/"#";
         // "-" should appear first in the regexp below as FF31 parses "[.-\w]" as a range
+        // 4: attribute; 5: attribute_string; 6: attribute_value
         '(?:\\[([-.\\w*]+)(?:=([\"\']?)([^\\]\"\']*)\\5)?\\])|' +  // "[name]", "[name=value]",
                                                                    // "[name="value"]",
                                                                    // "[name='value']"
-        '(\\))|' +                                                 // ")"
-        '(\\s*,\\s*)',                                             // ","
+        '(\\))|' +                                                 // 7: ")"
+        '(\\s*,\\s*)',                                             // 8: ","
     'g');
 
+/**
+ * These offsets should match the match-groups in `_SELECTOR_REGEXP` offsets.
+ */
+const enum SelectorRegexp {
+  ALL = 0,  // The whole match
+  NOT = 1,
+  TAG = 2,
+  PREFIX = 3,
+  ATTRIBUTE = 4,
+  ATTRIBUTE_STRING = 5,
+  ATTRIBUTE_VALUE = 6,
+  NOT_END = 7,
+  SEPARATOR = 8,
+}
 /**
  * A css selector contains an element name,
  * css classes and attribute/value pairs with the purpose
@@ -57,28 +71,37 @@ export class CssSelector {
     let inNot = false;
     _SELECTOR_REGEXP.lastIndex = 0;
     while (match = _SELECTOR_REGEXP.exec(selector)) {
-      if (match[1]) {
+      if (match[SelectorRegexp.NOT]) {
         if (inNot) {
-          throw new Error('Nesting :not is not allowed in a selector');
+          throw new Error('Nesting :not in a selector is not allowed');
         }
         inNot = true;
         current = new CssSelector();
         cssSelector.notSelectors.push(current);
       }
-      if (match[2]) {
-        current.setElement(match[2]);
+      const tag = match[SelectorRegexp.TAG];
+      if (tag) {
+        const prefix = match[SelectorRegexp.PREFIX];
+        if (prefix === '#') {
+          // #hash
+          current.addAttribute('id', tag.substr(1));
+        } else if (prefix === '.') {
+          // Class
+          current.addClassName(tag.substr(1));
+        } else {
+          // Element
+          current.setElement(tag);
+        }
       }
-      if (match[3]) {
-        current.addClassName(match[3]);
+      const attribute = match[SelectorRegexp.ATTRIBUTE];
+      if (attribute) {
+        current.addAttribute(attribute, match[SelectorRegexp.ATTRIBUTE_VALUE]);
       }
-      if (match[4]) {
-        current.addAttribute(match[4], match[6]);
-      }
-      if (match[7]) {
+      if (match[SelectorRegexp.NOT_END]) {
         inNot = false;
         current = cssSelector;
       }
-      if (match[8]) {
+      if (match[SelectorRegexp.SEPARATOR]) {
         if (inNot) {
           throw new Error('Multiple selectors in :not are not supported');
         }
diff --git a/packages/compiler/test/selector/selector_spec.ts b/packages/compiler/test/selector/selector_spec.ts
index 01fb5a8913..b61bc7ad44 100644
--- a/packages/compiler/test/selector/selector_spec.ts
+++ b/packages/compiler/test/selector/selector_spec.ts
@@ -330,6 +330,12 @@ import {el} from '@angular/platform-browser/testing/src/browser_util';
       expect(cssSelector.toString()).toEqual('[attrname=attrvalue]');
     });
 
+    it('should detect #some-value syntax and treat as attribute', () => {
+      const cssSelector = CssSelector.parse('#some-value')[0];
+      expect(cssSelector.attrs).toEqual(['id', 'some-value']);
+      expect(cssSelector.toString()).toEqual('[id=some-value]');
+    });
+
     it('should detect attr values with single quotes', () => {
       const cssSelector = CssSelector.parse('[attrname=\'attrvalue\']')[0];
       expect(cssSelector.attrs).toEqual(['attrname', 'attrvalue']);
@@ -381,7 +387,7 @@ import {el} from '@angular/platform-browser/testing/src/browser_util';
     it('should throw when nested :not', () => {
       expect(() => {
         CssSelector.parse('sometag:not(:not([attrname=attrvalue].someclass))')[0];
-      }).toThrowError('Nesting :not is not allowed in a selector');
+      }).toThrowError('Nesting :not in a selector is not allowed');
     });
 
     it('should throw when multiple selectors in :not', () => {
diff --git a/packages/core/test/acceptance/bootstrap_spec.ts b/packages/core/test/acceptance/bootstrap_spec.ts
new file mode 100644
index 0000000000..b11889bfb9
--- /dev/null
+++ b/packages/core/test/acceptance/bootstrap_spec.ts
@@ -0,0 +1,36 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {Component, NgModule} from '@angular/core';
+import {getComponentDef} from '@angular/core/src/render3/definition';
+import {BrowserModule} from '@angular/platform-browser';
+import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
+import {onlyInIvy, withBody} from '@angular/private/testing';
+
+describe('bootstrap', () => {
+  it('should bootstrap using #id selector', withBody('<div #my-app>', async() => {
+       try {
+         const ngModuleRef = await platformBrowserDynamic().bootstrapModule(MyAppModule);
+         expect(document.body.textContent).toEqual('works!');
+         ngModuleRef.destroy();
+       } catch (err) {
+         console.error(err);
+       }
+     }));
+});
+
+@Component({
+  selector: '#my-app',
+  template: 'works!',
+})
+export class MyAppComponent {
+}
+
+@NgModule({imports: [BrowserModule], declarations: [MyAppComponent], bootstrap: [MyAppComponent]})
+export class MyAppModule {
+}