diff --git a/packages/common/src/directives/styling_differ.ts b/packages/common/src/directives/styling_differ.ts
index 9ba3552bb1..972c15337d 100644
--- a/packages/common/src/directives/styling_differ.ts
+++ b/packages/common/src/directives/styling_differ.ts
@@ -212,11 +212,11 @@ function bulidMapFromValues(
     // case 1: map
     for (let i = 0; i < keys.length; i++) {
       let key = keys[i];
-      key = trim ? key.trim() : key;
       const value = (values as{[key: string]: any})[key];
 
       if (value !== undefined) {
-        setMapValues(map, key, value, parseOutUnits, allowSubKeys);
+        // Map uses untrimmed keys, so don't trim until passing to `setMapValues`
+        setMapValues(map, trim ? key.trim() : key, value, parseOutUnits, allowSubKeys);
       }
     }
   } else {
diff --git a/packages/core/test/acceptance/styling_spec.ts b/packages/core/test/acceptance/styling_spec.ts
index 811f8db763..4addfa16e2 100644
--- a/packages/core/test/acceptance/styling_spec.ts
+++ b/packages/core/test/acceptance/styling_spec.ts
@@ -2485,6 +2485,28 @@ describe('styling', () => {
     const div = fixture.nativeElement.querySelector('div');
     expect(getComputedStyle(div).width).toBe('10px');
   });
+
+  it('should allow classes with trailing and leading spaces in [ngClass]', () => {
+    @Component({
+      template: `
+        <div leading-space [ngClass]="{' foo': applyClasses}"></div>
+        <div trailing-space [ngClass]="{'foo ': applyClasses}"></div>
+      `
+    })
+    class Cmp {
+      applyClasses = true;
+    }
+
+    TestBed.configureTestingModule({declarations: [Cmp]});
+    const fixture = TestBed.createComponent(Cmp);
+    fixture.detectChanges();
+
+    const leading = fixture.nativeElement.querySelector('[leading-space]');
+    const trailing = fixture.nativeElement.querySelector('[trailing-space]');
+    expect(leading.className).toBe('foo', 'Expected class to be applied despite leading space.');
+    expect(trailing.className).toBe('foo', 'Expected class to be applied despite trailing space.');
+  });
+
 });
 
 function assertStyleCounters(countForSet: number, countForRemove: number) {