diff --git a/Cartfile.resolved b/Cartfile.resolved
index 32291f6..11ebc19 100644
--- a/Cartfile.resolved
+++ b/Cartfile.resolved
@@ -1 +1 @@
-github "trill-lang/FileCheck" "0.0.3"
+github "trill-lang/FileCheck" "0.0.4"
diff --git a/Carthage/Checkouts/FileCheck b/Carthage/Checkouts/FileCheck
index 482e229..0830734 160000
--- a/Carthage/Checkouts/FileCheck
+++ b/Carthage/Checkouts/FileCheck
@@ -1 +1 @@
-Subproject commit 482e22960391b02e3630ae3af4dce64d16dd63e7
+Subproject commit 083073480112406580f0242036a079f9f8b170ad
diff --git a/Sources/SwiftCheck/Arbitrary.swift b/Sources/SwiftCheck/Arbitrary.swift
index 755d2fe..ba885e1 100644
--- a/Sources/SwiftCheck/Arbitrary.swift
+++ b/Sources/SwiftCheck/Arbitrary.swift
@@ -314,7 +314,7 @@ extension String : Arbitrary {
 
 	/// The default shrinking function for `String` values.
 	public static func shrink(_ s : String) -> [String] {
-		return [Character].shrink([Character](s.characters)).map { String($0) }
+		return [Character].shrink(s.map{$0}).map { String($0) }
 	}
 }
 
diff --git a/Sources/SwiftCheck/CoArbitrary.swift b/Sources/SwiftCheck/CoArbitrary.swift
index 53f1388..582719a 100644
--- a/Sources/SwiftCheck/CoArbitrary.swift
+++ b/Sources/SwiftCheck/CoArbitrary.swift
@@ -71,7 +71,7 @@ extension String : CoArbitrary {
 		}
 		return comp(
 			Character.coarbitrary(x[x.startIndex]), 
-			String.coarbitrary(String(x[x.characters.index(after: x.startIndex)..<x.endIndex]))
+			String.coarbitrary(String(x[x.index(after: x.startIndex)..<x.endIndex]))
 		)
 	}
 }
diff --git a/Sources/SwiftCheck/Property.swift b/Sources/SwiftCheck/Property.swift
index ed69078..9faf894 100644
--- a/Sources/SwiftCheck/Property.swift
+++ b/Sources/SwiftCheck/Property.swift
@@ -670,7 +670,7 @@ private func printLabels(_ st : TestResult) {
 		let gAllLabels = st.labels.map({ t in
 			return t.0 + ", "
 		}).reduce("", +)
-		print("("  + gAllLabels[gAllLabels.startIndex..<gAllLabels.characters.index(gAllLabels.endIndex, offsetBy: -2)] + ")")
+		print("("  + gAllLabels[gAllLabels.startIndex..<gAllLabels.index(gAllLabels.endIndex, offsetBy: -2)] + ")")
 	}
 }
 
diff --git a/Tests/SwiftCheckTests/ComplexSpec.swift b/Tests/SwiftCheckTests/ComplexSpec.swift
index 225f66b..dde0bf0 100644
--- a/Tests/SwiftCheckTests/ComplexSpec.swift
+++ b/Tests/SwiftCheckTests/ComplexSpec.swift
@@ -46,7 +46,7 @@ class ComplexSpec : XCTestCase {
 			/// CHECKEMAIL: *** Passed 1 test
 			/// CHECKEMAIL-NEXT: .
 			property("Generated email addresses contain 1 @", arguments: args) <- forAll(emailGen) { (e : String) in
-				return e.filter({ $0 == "@" }).characters.count == 1
+				return (e.filter({ $0 == "@" }) as [Character]).count == 1
 			}.once
 		})
 	}
@@ -70,7 +70,7 @@ class ComplexSpec : XCTestCase {
 			/// CHECKIPV6: *** Passed 100 tests
 			/// CHECKIPV6-NEXT: .
 			property("Generated IPs contain 3 sections") <- forAll(ipGen) { (e : String) in
-				return e.filter({ $0 == ":" }).characters.count == 3
+				return (e.filter({ $0 == ":" }) as [Character]).count == 3
 			}
 		})
 	}
@@ -91,6 +91,6 @@ func glue(_ parts : [Gen<String>]) -> Gen<String> {
 
 extension String {
 	fileprivate var initial : String {
-		return String(self[self.startIndex..<self.characters.index(before: self.endIndex)])
+		return String(self[self.startIndex..<self.index(before: self.endIndex)])
 	}
 }