diff --git a/.travis.yml b/.travis.yml
index 32a96101..9fc8e935 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,7 +5,7 @@ matrix:
   include:
   - os: osx
     language: objective-c
-    osx_image: xcode8.2
+    osx_image: xcode8.3
     before_install:
     - export PATH=/usr/local/opt/llvm/bin:"${PATH}"
     - brew update
@@ -33,10 +33,10 @@ matrix:
     - sudo rm -f /usr/bin/llvm-config
     - sudo ln -s /usr/bin/llvm-config-${LLVM_API_VERSION} /usr/bin/llvm-config
     - wget -q -O - https://swift.org/keys/all-keys.asc | gpg --import -
-    - wget https://swift.org/builds/swift-3.0.2-release/ubuntu1404/swift-3.0.2-RELEASE/swift-3.0.2-RELEASE-ubuntu14.04.tar.gz
-    - tar xzf swift-3.0.2-RELEASE-ubuntu14.04.tar.gz
-    - export PATH=${PWD}/swift-3.0.2-RELEASE-ubuntu14.04/usr/bin:"${PATH}"
-    - sudo ./swift-3.0.2-RELEASE-ubuntu14.04/usr/bin/swift utils/make-pkgconfig.swift
+    - wget https://swift.org/builds/swift-3.1-release/ubuntu1404/swift-3.1-RELEASE/swift-3.1-RELEASE-ubuntu14.04.tar.gz
+    - tar xzf swift-3.1-RELEASE-ubuntu14.04.tar.gz
+    - export PATH=${PWD}/swift-3.1-RELEASE-ubuntu14.04/usr/bin:"${PATH}"
+    - sudo ./swift-3.1-RELEASE-ubuntu14.04/usr/bin/swift utils/make-pkgconfig.swift
     script:
     - swift test
 notifications:
diff --git a/README.md b/README.md
index 78da280d..e7bb8aad 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,7 @@ Plus, it provides common wrappers around oft-used types like `Function`, `Global
 There are a couple, annoying steps you need to get it working before it'll
 build.
 
-- Install LLVM 3.9 using your favorite package manager. For example:
+- Install LLVM 4.0 using your favorite package manager. For example:
   - `brew install llvm`
 - Ensure `llvm-config` is in your `PATH`
   - That will reside in the `/bin` folder wherever your package manager
diff --git a/Sources/LLVM/BasicBlock.swift b/Sources/LLVM/BasicBlock.swift
index 6d7f01e1..63ee2121 100644
--- a/Sources/LLVM/BasicBlock.swift
+++ b/Sources/LLVM/BasicBlock.swift
@@ -65,7 +65,7 @@ public struct BasicBlock: IRValue {
 
   /// Deletes the basic block from its containing function.
   /// - note: This does not remove breaks to this block from the
-  ///         function. Ensure you have removed all insructions that reference
+  ///         function. Ensure you have removed all instructions that reference
   ///         this basic block before deleting it.
   public func delete() {
     LLVMDeleteBasicBlock(llvm)
diff --git a/Sources/LLVM/Constant.swift b/Sources/LLVM/Constant.swift
index 12f4a250..ab8c22e3 100644
--- a/Sources/LLVM/Constant.swift
+++ b/Sources/LLVM/Constant.swift
@@ -14,13 +14,6 @@ public enum Signed: IntegralConstantRepresentation {}
 /// Represents floating types and operations.
 public enum Floating: ConstantRepresentation {}
 
-// FIXME: When upgrading to Swift 3.1, move this into `Constant`.
-internal enum InternalConstantRepresentation {
-  case unsigned
-  case signed
-  case floating
-}
-
 /// A `Constant` represents a value initialized to a constant.  Constant values
 /// may be manipulated with standard Swift arithmetic operations and used with
 /// standard IR Builder instructions like any other operand.  The difference
@@ -31,8 +24,15 @@ internal enum InternalConstantRepresentation {
 /// disallow mixed-type arithmetic.  Use the `cast` family of operations to
 /// safely convert constants to other representations.
 public struct Constant<Repr: ConstantRepresentation>: IRValue {
+  fileprivate enum Representation {
+    case unsigned
+    case signed
+    case floating
+  }
+  fileprivate let repr: Representation
+
   internal let llvm: LLVMValueRef
-  internal let repr: InternalConstantRepresentation
+
   internal init(llvm: LLVMValueRef!) {
     self.llvm = llvm
 
diff --git a/Sources/LLVM/Function.swift b/Sources/LLVM/Function.swift
index 3ef270c2..6ed3b363 100644
--- a/Sources/LLVM/Function.swift
+++ b/Sources/LLVM/Function.swift
@@ -181,7 +181,7 @@ public class Function: IRGlobal {
 
   /// Deletes the function from its containing module.
   /// - note: This does not remove calls to this function from the
-  ///         module. Ensure you have removed all insructions that reference
+  ///         module. Ensure you have removed all instructions that reference
   ///         this function before deleting it.
   public func delete() {
     LLVMDeleteFunction(llvm)
diff --git a/Sources/LLVM/Global.swift b/Sources/LLVM/Global.swift
index ce858f5a..ec7a5bd6 100644
--- a/Sources/LLVM/Global.swift
+++ b/Sources/LLVM/Global.swift
@@ -130,7 +130,7 @@ public struct Global: IRGlobal {
 
   /// Deletes the global variable from its containing module.
   /// - note: This does not remove references to this global from the
-  ///         module. Ensure you have removed all insructions that reference
+  ///         module. Ensure you have removed all instructions that reference
   ///         this global before deleting it.
   public func delete() {
     LLVMDeleteGlobal(llvm)
diff --git a/Tests/LLVMTests/FileCheck.swift b/Tests/LLVMTests/FileCheck.swift
index 369873e7..ca2f5aa4 100644
--- a/Tests/LLVMTests/FileCheck.swift
+++ b/Tests/LLVMTests/FileCheck.swift
@@ -2,8 +2,6 @@ import Foundation
 
 #if os(Linux)
   import Glibc
-
-  typealias NSRegularExpression = RegularExpression
 #else
   import Darwin
 #endif
diff --git a/utils/make-pkgconfig.swift b/utils/make-pkgconfig.swift
index b09acfad..43cc1b3f 100644
--- a/utils/make-pkgconfig.swift
+++ b/utils/make-pkgconfig.swift
@@ -2,7 +2,6 @@
 import Foundation
 
 #if os(Linux)
-  typealias Process = Task
   let libCPP = "-L/usr/lib -lc++"
 #elseif os(macOS)
   let libCPP = "-lc++"