diff --git a/InjectionBundle/SwiftEval.swift b/InjectionBundle/SwiftEval.swift
index bc6d5b7d..404dd903 100644
--- a/InjectionBundle/SwiftEval.swift
+++ b/InjectionBundle/SwiftEval.swift
@@ -5,7 +5,7 @@
 //  Created by John Holdsworth on 02/11/2017.
 //  Copyright © 2017 John Holdsworth. All rights reserved.
 //
-//  $Id: //depot/ResidentEval/InjectionBundle/SwiftEval.swift#158 $
+//  $Id: //depot/ResidentEval/InjectionBundle/SwiftEval.swift#160 $
 //
 //  Basic implementation of a Swift "eval()" including the
 //  mechanics of recompiling a class and loading the new
@@ -451,8 +451,26 @@ public class SwiftEval: NSObject {
         return tmpfile
     }
 
+    lazy var loadXCTest: () = {
+        #if os(macOS)
+        let sdk = "MacOSX"
+        #elseif os(tvOS)
+        let sdk = "AppleTVSimulator"
+        #elseif targetEnvironment(simulator)
+        let sdk = "iPhoneSimulator"
+        #else
+        let sdk = "iPhoneOS"
+        #endif
+
+        if dlopen("\(xcodeDev)/Platforms/\(sdk).platform/Developer/Library/Frameworks/XCTest.framework/XCTest", RTLD_LAZY) == nil {
+            debug(String(cString: dlerror()))
+        }
+    }()
+
     @objc func loadAndInject(tmpfile: String, oldClass: AnyClass? = nil) throws -> [AnyClass] {
 
+        _ = loadXCTest
+
         print("💉 Loading .dylib ...")
         // load patched .dylib into process with new version of class
         guard let dl = dlopen("\(tmpfile).dylib", RTLD_NOW) else {
diff --git a/InjectionBundle/SwiftInjection.swift b/InjectionBundle/SwiftInjection.swift
index 958b81a7..fd7c6a1b 100644
--- a/InjectionBundle/SwiftInjection.swift
+++ b/InjectionBundle/SwiftInjection.swift
@@ -5,7 +5,7 @@
 //  Created by John Holdsworth on 05/11/2017.
 //  Copyright © 2017 John Holdsworth. All rights reserved.
 //
-//  $Id: //depot/ResidentEval/InjectionBundle/SwiftInjection.swift#115 $
+//  $Id: //depot/ResidentEval/InjectionBundle/SwiftInjection.swift#116 $
 //
 //  Cut-down version of code injection in Swift. Uses code
 //  from SwiftEval.swift to recompile and reload class.
@@ -222,6 +222,7 @@ public class SwiftInjection: NSObject {
         for suffix in SwiftTrace.swiftFunctionSuffixes {
             findSwiftSymbols(dylib, suffix) { (loadedFunc, symbol, _, _) in
                 guard let existing = dlsym(main, symbol),
+                    UnsafeRawPointer(existing) != loadedFunc,
                     let current = SwiftTrace.interposed(replacee: existing) else {
                     return
                 }
diff --git a/InjectionIII/Info.plist b/InjectionIII/Info.plist
index ff437168..d11d6295 100644
--- a/InjectionIII/Info.plist
+++ b/InjectionIII/Info.plist
@@ -19,7 +19,7 @@
 	<key>CFBundleShortVersionString</key>
 	<string>$(MARKETING_VERSION)</string>
 	<key>CFBundleVersion</key>
-	<string>5633</string>
+	<string>5638</string>
 	<key>LSApplicationCategoryType</key>
 	<string>public.app-category.developer-tools</string>
 	<key>LSMinimumSystemVersion</key>
diff --git a/SwiftTrace b/SwiftTrace
index 1dc7fb16..25d60feb 160000
--- a/SwiftTrace
+++ b/SwiftTrace
@@ -1 +1 @@
-Subproject commit 1dc7fb167f4b04709894c166cda8460aa449d9a7
+Subproject commit 25d60feb08275bbf0c05f98cc32098ed70b9384b