diff --git a/core-foundation-sys/src/characterset.rs b/core-foundation-sys/src/characterset.rs
new file mode 100644
index 0000000..6b347a5
--- /dev/null
+++ b/core-foundation-sys/src/characterset.rs
@@ -0,0 +1,58 @@
+// Copyright 2019 The Servo Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::os::raw::c_void;
+use base::{Boolean, CFAllocatorRef, CFIndex, CFRange, CFTypeID};
+use data::CFDataRef;
+use string::{CFStringRef, UniChar};
+
+pub type CFCharacterSetPredefinedSet = CFIndex;
+
+// Members of CFCharacterSetPredefinedSet enum
+pub static kCFCharacterSetControl: CFCharacterSetPredefinedSet = 1;
+pub static kCFCharacterSetWhitespace: CFCharacterSetPredefinedSet = 2;
+pub static kCFCharacterSetWhitespaceAndNewline: CFCharacterSetPredefinedSet = 3;
+pub static kCFCharacterSetDecimalDigit: CFCharacterSetPredefinedSet = 4;
+pub static kCFCharacterSetLetter: CFCharacterSetPredefinedSet = 5;
+pub static kCFCharacterSetLowercaseLetter: CFCharacterSetPredefinedSet = 6;
+pub static kCFCharacterSetUppercaseLetter: CFCharacterSetPredefinedSet = 7;
+pub static kCFCharacterSetNonBase: CFCharacterSetPredefinedSet = 8;
+pub static kCFCharacterSetDecomposable: CFCharacterSetPredefinedSet = 9;
+pub static kCFCharacterSetAlphaNumeric: CFCharacterSetPredefinedSet = 10;
+pub static kCFCharacterSetPunctuation: CFCharacterSetPredefinedSet = 11;
+pub static kCFCharacterSetIllegal: CFCharacterSetPredefinedSet = 12;
+pub static kCFCharacterSetCapitalizedLetter: CFCharacterSetPredefinedSet = 13;
+pub static kCFCharacterSetSymbol: CFCharacterSetPredefinedSet = 14;
+pub static kCFCharacterSetNewline: CFCharacterSetPredefinedSet = 15;
+
+#[repr(C)]
+pub struct __CFCharacterSet(c_void);
+
+pub type CFCharacterSetRef = *const __CFCharacterSet;
+pub type CFMutableCharacterSetRef = *const __CFCharacterSet;
+
+extern {
+    pub fn CFCharacterSetGetTypeID() -> CFTypeID;
+    pub fn CFCharacterSetGetPredefined(theSetIdentifier: CFCharacterSetPredefinedSet) -> CFCharacterSetRef;
+    pub fn CFCharacterSetCreateWithCharactersInRange(alloc: CFAllocatorRef, theRange: CFRange) -> CFCharacterSetRef;
+    pub fn CFCharacterSetCreateWithCharactersInString(alloc: CFAllocatorRef, theString: CFStringRef) -> CFCharacterSetRef;
+    pub fn CFCharacterSetCreateWithBitmapRepresentation(alloc: CFAllocatorRef, theData: CFDataRef) -> CFCharacterSetRef;
+    pub fn CFCharacterSetCreateMutable(alloc: CFAllocatorRef) -> CFMutableCharacterSetRef;
+    pub fn CFCharacterSetCreateCopy(alloc: CFAllocatorRef, theSet: CFCharacterSetRef) -> CFCharacterSetRef;
+    pub fn CFCharacterSetCreateMutableCopy(alloc: CFAllocatorRef, theSet: CFCharacterSetRef) -> CFMutableCharacterSetRef;
+    pub fn CFCharacterSetIsCharacterMember(theSet: CFCharacterSetRef, theChar: UniChar) -> Boolean;
+    pub fn CFCharacterSetCreateBitmapRepresentation(alloc: CFAllocatorRef, theSet: CFCharacterSetRef) -> CFDataRef;
+    pub fn CFCharacterSetAddCharactersInRange(theSet: CFMutableCharacterSetRef, theRange: CFRange);
+    pub fn CFCharacterSetRemoveCharactersInRange(theSet: CFMutableCharacterSetRef, theRange: CFRange);
+    pub fn CFCharacterSetAddCharactersInString(theSet: CFMutableCharacterSetRef,  theString: CFStringRef);
+    pub fn CFCharacterSetRemoveCharactersInString(theSet: CFMutableCharacterSetRef, theString: CFStringRef);
+    pub fn CFCharacterSetUnion(theSet: CFMutableCharacterSetRef, theOtherSet: CFCharacterSetRef);
+    pub fn CFCharacterSetIntersect(theSet: CFMutableCharacterSetRef, theOtherSet: CFCharacterSetRef);
+    pub fn CFCharacterSetInvert(theSet: CFMutableCharacterSetRef);
+}
diff --git a/core-foundation-sys/src/lib.rs b/core-foundation-sys/src/lib.rs
index e03cddb..9b1056b 100644
--- a/core-foundation-sys/src/lib.rs
+++ b/core-foundation-sys/src/lib.rs
@@ -14,6 +14,7 @@ pub mod array;
 pub mod attributed_string;
 pub mod base;
 pub mod bundle;
+pub mod characterset;
 pub mod data;
 pub mod date;
 pub mod dictionary;