diff --git a/Sources/Datadog/Core/AutoInstrumentation/MethodSwizzler.swift b/Sources/Datadog/Core/AutoInstrumentation/MethodSwizzler.swift
index 4760a031b6..84612ae654 100644
--- a/Sources/Datadog/Core/AutoInstrumentation/MethodSwizzler.swift
+++ b/Sources/Datadog/Core/AutoInstrumentation/MethodSwizzler.swift
@@ -62,8 +62,8 @@ internal class MethodSwizzler<TypedIMP, TypedBlockIMP> {
     @discardableResult
     func swizzle(
         _ foundMethod: FoundMethod,
-        impProvider: (TypedIMP) -> TypedBlockIMP,
-        onlyIfNonSwizzled: Bool = false
+        onlyIfNonSwizzled: Bool = false,
+        impProvider: (TypedIMP) -> TypedBlockIMP
     ) -> Bool {
         sync {
             if onlyIfNonSwizzled &&
diff --git a/Sources/Datadog/Core/AutoInstrumentation/URLSessionSwizzler.swift b/Sources/Datadog/Core/AutoInstrumentation/URLSessionSwizzler.swift
index 1be2eb069f..a45a6d1b1e 100644
--- a/Sources/Datadog/Core/AutoInstrumentation/URLSessionSwizzler.swift
+++ b/Sources/Datadog/Core/AutoInstrumentation/URLSessionSwizzler.swift
@@ -146,14 +146,13 @@ internal class URLSessionSwizzler {
             typealias BlockIMP = @convention(block) (URLSessionTask) -> Void
             swizzle(
                 foundMethod,
-                impProvider: { currentTypedImp -> BlockIMP in
-                    return { impSelf in
-                        impSelf.consumePayloads { $0(.starting(impSelf.currentRequest)) }
-                        return currentTypedImp(impSelf, Self.selector)
-                    }
-                },
                 onlyIfNonSwizzled: true
-            )
+            ) { currentTypedImp -> BlockIMP in
+                return { impSelf in
+                    impSelf.consumePayloads { $0(.starting(impSelf.currentRequest)) }
+                    return currentTypedImp(impSelf, Self.selector)
+                }
+            }
         }
     }
 }
diff --git a/Sources/Datadog/Core/Persistence/Files/File.swift b/Sources/Datadog/Core/Persistence/Files/File.swift
index 1f9f26a5d5..bf552529ef 100644
--- a/Sources/Datadog/Core/Persistence/Files/File.swift
+++ b/Sources/Datadog/Core/Persistence/Files/File.swift
@@ -46,60 +46,84 @@ internal struct File: WritableFile, ReadableFile {
     func append(data: Data) throws {
         let fileHandle = try FileHandle(forWritingTo: url)
 
+        // NOTE: RUMM-669
+        // https://github.com/DataDog/dd-sdk-ios/issues/214
+        // https://en.wikipedia.org/wiki/Xcode#11.x_series
+        // compiler version needs to have iOS 13.4+ as base SDK
+        #if compiler(>=5.2)
+        /**
+         Even though the `fileHandle.seekToEnd()` should be available since iOS 13.0:
+         ```
+         @available(OSX 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+         public func seekToEnd() throws -> UInt64
+         ```
+         it crashes on iOS Simulators prior to iOS 13.4:
+         ```
+         Symbol not found: _$sSo12NSFileHandleC10FoundationE9seekToEnds6UInt64VyKF
+         ```
+         This is fixed in iOS 14/Xcode 12
+        */
         if #available(iOS 13.4, *) {
-            /**
-             Even though the `fileHandle.seekToEnd()` should be available since iOS 13.0:
-             ```
-             @available(OSX 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
-             public func seekToEnd() throws -> UInt64
-             ```
-             it crashes on iOS Simulators prior to iOS 13.4:
-             ```
-             Symbol not found: _$sSo12NSFileHandleC10FoundationE9seekToEnds6UInt64VyKF
-             ```
-            */
             defer { try? fileHandle.close() }
             try fileHandle.seekToEnd()
             try fileHandle.write(contentsOf: data)
         } else {
-            defer {
-                try? objcExceptionHandler.rethrowToSwift {
-                    fileHandle.closeFile()
-                }
-            }
+            try legacyAppend(data, to: fileHandle)
+        }
+        #else
+        try legacyAppend(data, to: fileHandle)
+        #endif
+    }
 
-            try objcExceptionHandler.rethrowToSwift {
-                fileHandle.seekToEndOfFile()
-                fileHandle.write(data)
+    private func legacyAppend(_ data: Data, to fileHandle: FileHandle) throws {
+        defer {
+            try? objcExceptionHandler.rethrowToSwift {
+                fileHandle.closeFile()
             }
         }
+        try objcExceptionHandler.rethrowToSwift {
+            fileHandle.seekToEndOfFile()
+            fileHandle.write(data)
+        }
     }
 
     func read() throws -> Data {
         let fileHandle = try FileHandle(forReadingFrom: url)
 
+        // NOTE: RUMM-669
+        // https://github.com/DataDog/dd-sdk-ios/issues/214
+        // https://en.wikipedia.org/wiki/Xcode#11.x_series
+        // compiler version needs to have iOS 13.4+ as base SDK
+        #if compiler(>=5.2)
+        /**
+         Even though the `fileHandle.seekToEnd()` should be available since iOS 13.0:
+         ```
+         @available(OSX 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+         public func readToEnd() throws -> Data?
+         ```
+         it crashes on iOS Simulators prior to iOS 13.4:
+         ```
+         Symbol not found: _$sSo12NSFileHandleC10FoundationE9readToEndAC4DataVSgyKF
+         ```
+        This is fixed in iOS 14/Xcode 12
+        */
         if #available(iOS 13.4, *) {
-            /**
-             Even though the `fileHandle.seekToEnd()` should be available since iOS 13.0:
-             ```
-             @available(OSX 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
-             public func readToEnd() throws -> Data?
-             ```
-             it crashes on iOS Simulators prior to iOS 13.4:
-             ```
-             Symbol not found: _$sSo12NSFileHandleC10FoundationE9readToEndAC4DataVSgyKF
-             ```
-            */
             defer { try? fileHandle.close() }
             return try fileHandle.readToEnd() ?? Data()
         } else {
-            defer {
-                try? objcExceptionHandler.rethrowToSwift {
-                    fileHandle.closeFile()
-                }
-            }
-            return fileHandle.readDataToEndOfFile()
+            return try legacyRead(from: fileHandle)
+        }
+        #else
+        return try legacyRead(from: fileHandle)
+        #endif
+    }
+
+    private func legacyRead(from fileHandle: FileHandle) throws -> Data {
+        let data = fileHandle.readDataToEndOfFile()
+        try? objcExceptionHandler.rethrowToSwift {
+            fileHandle.closeFile()
         }
+        return data
     }
 
     func size() throws -> UInt64 {
diff --git a/Tests/DatadogTests/Datadog/Core/AutoInstrumentation/MethodSwizzlerTests.swift b/Tests/DatadogTests/Datadog/Core/AutoInstrumentation/MethodSwizzlerTests.swift
index 8475c04842..71fac60359 100644
--- a/Tests/DatadogTests/Datadog/Core/AutoInstrumentation/MethodSwizzlerTests.swift
+++ b/Tests/DatadogTests/Datadog/Core/AutoInstrumentation/MethodSwizzlerTests.swift
@@ -107,7 +107,7 @@ class MethodSwizzlerTests: XCTestCase {
         let secondSwizzlingReturnValue = "Second swizzling"
         let newImp: TypedBlockIMPReturnString = { _ in secondSwizzlingReturnValue }
         XCTAssertFalse(
-            swizzler.swizzle(foundMethod, impProvider: { _ in newImp }, onlyIfNonSwizzled: true),
+            swizzler.swizzle(foundMethod, onlyIfNonSwizzled: true) { _ in newImp },
             "Already swizzled method should not be swizzled again"
         )
 
@@ -130,12 +130,11 @@ class MethodSwizzlerTests: XCTestCase {
         XCTAssertFalse(
             swizzler.swizzle(
                 foundMethod,
-                impProvider: { _ -> TypedBlockIMPReturnString in
-                    XCTFail("New IMP should not be created after error")
-                    return newIMPReturnString
-                },
                 onlyIfNonSwizzled: true
-            ),
+            ) { _ -> TypedBlockIMPReturnString in
+                XCTFail("New IMP should not be created after error")
+                return newIMPReturnString
+            },
             "Already swizzled method should not be swizzled again"
         )
     }
@@ -178,13 +177,12 @@ class MethodSwizzlerTests: XCTestCase {
         DispatchQueue.concurrentPerform(iterations: iterations) { _ in
             swizzler.swizzle(
                 foundMethod,
-                impProvider: { originalImp -> TypedBlockIMPReturnString in
-                    return { impSelf -> String in
-                        return originalImp(impSelf, selector).appending(appendString)
-                    }
-                },
                 onlyIfNonSwizzled: true
-            )
+            ) { originalImp -> TypedBlockIMPReturnString in
+                return { impSelf -> String in
+                    return originalImp(impSelf, selector).appending(appendString)
+                }
+            }
             expectation.fulfill()
         }