diff --git a/packages/compiler-cli/src/diagnostics/expression_type.ts b/packages/compiler-cli/src/diagnostics/expression_type.ts
index 85a7ce93ed..abf2613cf7 100644
--- a/packages/compiler-cli/src/diagnostics/expression_type.ts
+++ b/packages/compiler-cli/src/diagnostics/expression_type.ts
@@ -304,6 +304,10 @@ export class AstType implements AstVisitor {
   }
 
   visitPrefixNot(ast: PrefixNot) {
+    // If we are producing diagnostics, visit the children
+    if (this.diagnostics) {
+      visitAstChildren(ast, this);
+    }
     // The type of a prefix ! is always boolean.
     return this.query.getBuiltinType(BuiltinType.Boolean);
   }
diff --git a/packages/compiler-cli/test/diagnostics/expression_diagnostics_spec.ts b/packages/compiler-cli/test/diagnostics/expression_diagnostics_spec.ts
index 371c913135..2b7c581407 100644
--- a/packages/compiler-cli/test/diagnostics/expression_diagnostics_spec.ts
+++ b/packages/compiler-cli/test/diagnostics/expression_diagnostics_spec.ts
@@ -98,6 +98,9 @@ describe('expression diagnostics', () => {
      () => reject(
          '<div *ngIf="persson">{{person.name.first}}</div>',
          'Identifier \'persson\' is not defined'));
+  it('should reject *ngIf of misspelled identifier in PrefixNot node',
+     () =>
+         reject('<div *ngIf="people && !persson"></div>', 'Identifier \'persson\' is not defined'));
   it('should accept an *ngFor', () => accept(`
       <div *ngFor="let p of people">
         {{p.name.first}} {{p.name.last}}