diff --git a/Foundation/NSString.swift b/Foundation/NSString.swift
index 87eb12ebf8..fc4ae5ddc6 100644
--- a/Foundation/NSString.swift
+++ b/Foundation/NSString.swift
@@ -405,15 +405,39 @@ extension NSString {
     }
     
     public func rangeOfCharacterFromSet(searchSet: NSCharacterSet) -> NSRange {
-        NSUnimplemented()
+        return rangeOfCharacterFromSet(searchSet, options: [])
     }
     
     public func rangeOfCharacterFromSet(searchSet: NSCharacterSet, options mask: NSStringCompareOptions) -> NSRange {
-        NSUnimplemented()
+        return rangeOfCharacterFromSet(searchSet, options: mask, range: NSMakeRange(0, length))
     }
     
     public func rangeOfCharacterFromSet(searchSet: NSCharacterSet, options mask: NSStringCompareOptions, range searchRange: NSRange) -> NSRange {
-        NSUnimplemented()
+        if mask.contains(.RegularExpressionSearch) {
+            NSUnimplemented()
+        }
+        if searchRange.length == 0 {
+            return NSMakeRange(NSNotFound, 0)
+        }
+        
+#if os(Linux)
+        var cfflags = CFStringCompareFlags(mask.rawValue)
+        if mask.contains(.LiteralSearch) {
+            cfflags |= UInt(kCFCompareNonliteral)
+        }
+#else
+        var cfflags = CFStringCompareFlags(rawValue: mask.rawValue)
+        if mask.contains(.LiteralSearch) {
+            cfflags.unionInPlace(.CompareNonliteral)
+        }
+#endif
+        var result = CFRangeMake(kCFNotFound, 0)
+
+        if CFStringFindCharacterFromSet(_cfObject, searchSet._cfObject, CFRangeMake(searchRange.location, searchRange.length), cfflags, &result) {
+            return NSMakeRange(result.location, result.length)
+        } else {
+            return NSMakeRange(NSNotFound, 0)
+        }
     }
     
     public func rangeOfComposedCharacterSequenceAtIndex(index: Int) -> NSRange {
diff --git a/TestFoundation/TestNSString.swift b/TestFoundation/TestNSString.swift
index 8eda160cf1..ff3bb0528f 100644
--- a/TestFoundation/TestNSString.swift
+++ b/TestFoundation/TestNSString.swift
@@ -34,6 +34,7 @@ class TestNSString : XCTestCase {
             ("test_FromNullTerminatedCStringInASCII", test_FromNullTerminatedCStringInASCII ),
             ("test_FromNullTerminatedCStringInUTF8", test_FromNullTerminatedCStringInUTF8 ),
             ("test_FromMalformedNullTerminatedCStringInUTF8", test_FromMalformedNullTerminatedCStringInUTF8 ),
+            ("test_rangeOfCharacterFromSet", test_rangeOfCharacterFromSet ),
         ]
     }
     
@@ -141,4 +142,14 @@ class TestNSString : XCTestCase {
         let string = NSString(CString: bytes.map { Int8(bitPattern: $0) }, encoding: NSUTF8StringEncoding)
         XCTAssertNil(string)
     }
-}
\ No newline at end of file
+
+    func test_rangeOfCharacterFromSet() {
+        let string: NSString = "0Az"
+        let letters = NSCharacterSet.letterCharacterSet()
+        let decimalDigits = NSCharacterSet.decimalDigitCharacterSet()
+        XCTAssertEqual(string.rangeOfCharacterFromSet(letters).location, 1)
+        XCTAssertEqual(string.rangeOfCharacterFromSet(decimalDigits).location, 0)
+        XCTAssertEqual(string.rangeOfCharacterFromSet(letters, options: [.BackwardsSearch]).location, 2)
+        XCTAssertEqual(string.rangeOfCharacterFromSet(letters, options: [], range: NSMakeRange(2, 1)).location, 2)
+    }
+}