diff --git a/.swiftformat b/.swiftformat
index 1084e4c54..e639ee783 100644
--- a/.swiftformat
+++ b/.swiftformat
@@ -1,10 +1,12 @@
 # file options
 
+--exclude .build
+
 # format options
 
---self insert 
---patternlet inline 
---stripunusedargs unnamed-only 
+--self insert
+--patternlet inline
+--stripunusedargs unnamed-only
 --comments ignore
 
 # rules
diff --git a/Sources/AsyncHTTPClient/HTTPHandler.swift b/Sources/AsyncHTTPClient/HTTPHandler.swift
index 20c6fec7f..45810daf2 100644
--- a/Sources/AsyncHTTPClient/HTTPHandler.swift
+++ b/Sources/AsyncHTTPClient/HTTPHandler.swift
@@ -19,7 +19,6 @@ import NIOHTTP1
 import NIOSSL
 
 extension HTTPClient {
-
     /// Represent request body.
     public struct Body {
         /// Chunk provider.
@@ -333,7 +332,7 @@ extension HTTPClientResponseDelegate {
 
     public func didSendRequest(task: HTTPClient.Task<Response>) {}
 
-    public func didReceiveHead(task: HTTPClient.Task<Response>, _: HTTPResponseHead)  -> EventLoopFuture<Void> { return task.eventLoop.makeSucceededFuture(()) }
+    public func didReceiveHead(task: HTTPClient.Task<Response>, _: HTTPResponseHead) -> EventLoopFuture<Void> { return task.eventLoop.makeSucceededFuture(()) }
 
     public func didReceivePart(task: HTTPClient.Task<Response>, _: ByteBuffer) -> EventLoopFuture<Void> { return task.eventLoop.makeSucceededFuture(()) }
 
diff --git a/Tests/AsyncHTTPClientTests/HTTPClientInternalTests.swift b/Tests/AsyncHTTPClientTests/HTTPClientInternalTests.swift
index 486a4e249..7c19cde2c 100644
--- a/Tests/AsyncHTTPClientTests/HTTPClientInternalTests.swift
+++ b/Tests/AsyncHTTPClientTests/HTTPClientInternalTests.swift
@@ -194,4 +194,3 @@ class HTTPClientInternalTests: XCTestCase {
         XCTAssertEqual(delegate.reads, 3)
     }
 }
-
diff --git a/Tests/AsyncHTTPClientTests/HTTPClientTests.swift b/Tests/AsyncHTTPClientTests/HTTPClientTests.swift
index 8e0a61230..c6a7f664b 100644
--- a/Tests/AsyncHTTPClientTests/HTTPClientTests.swift
+++ b/Tests/AsyncHTTPClientTests/HTTPClientTests.swift
@@ -44,7 +44,7 @@ class HTTPClientTests: XCTestCase {
         let response = try httpClient.get(url: "http://localhost:\(httpBin.port)/get").wait()
         XCTAssertEqual(.ok, response.status)
     }
-    
+
     func testGetWithSharedEventLoopGroup() throws {
         let httpBin = HttpBin()
         let elg = MultiThreadedEventLoopGroup(numberOfThreads: 8)
@@ -53,12 +53,12 @@ class HTTPClientTests: XCTestCase {
             try! elg.syncShutdownGracefully()
             httpBin.shutdown()
         }
-        
+
         let delegate = TestHTTPDelegate()
         let request = try HTTPClient.Request(url: "http://localhost:\(httpBin.port)/events/10/1")
         let task = httpClient.execute(request: request, delegate: delegate)
         let expectedEventLoop = task.eventLoop
-        task.futureResult.whenComplete { (_) in
+        task.futureResult.whenComplete { _ in
             XCTAssertTrue(expectedEventLoop.inEventLoop)
         }
         try task.wait()
@@ -154,7 +154,7 @@ class HTTPClientTests: XCTestCase {
         let hostName = try decoder.decode([String: String].self, from: responseData)["data"]
         XCTAssert(hostName == "127.0.0.1")
     }
-    
+
     func testPercentEncoded() throws {
         let httpBin = HttpBin()
         let httpClient = HTTPClient(eventLoopGroupProvider: .createNew)
@@ -162,7 +162,7 @@ class HTTPClientTests: XCTestCase {
             try! httpClient.syncShutdown()
             httpBin.shutdown()
         }
-        
+
         let response = try httpClient.get(url: "http://localhost:\(httpBin.port)/percent%20encoded").wait()
         XCTAssertEqual(.ok, response.status)
     }
diff --git a/docker/Dockerfile b/docker/Dockerfile
index b177481f3..9fb59d73c 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -23,6 +23,13 @@ RUN gem install jazzy --no-ri --no-rdoc
 RUN mkdir -p $HOME/.tools
 RUN echo 'export PATH="$HOME/.tools:$PATH"' >> $HOME/.profile
 
-# script to allow mapping framepointers on linux
+# script to allow mapping framepointers on linux (until part of the toolchain)
 RUN wget -q https://raw.githubusercontent.com/apple/swift/master/utils/symbolicate-linux-fatal -O $HOME/.tools/symbolicate-linux-fatal
 RUN chmod 755 $HOME/.tools/symbolicate-linux-fatal
+
+# swiftformat (until part of the toolchain)
+
+ARG swiftformat_version=0.40.11
+RUN git clone --branch $swiftformat_version --depth 1 https://github.com/nicklockwood/SwiftFormat $HOME/.tools/swift-format
+RUN cd $HOME/.tools/swift-format && swift build -c release
+RUN ln -s $HOME/.tools/swift-format/.build/release/swiftformat $HOME/.tools/swiftformat
diff --git a/scripts/sanity.sh b/scripts/sanity.sh
index 999cb0d4d..04f1c5f2e 100755
--- a/scripts/sanity.sh
+++ b/scripts/sanity.sh
@@ -28,10 +28,23 @@ else
   printf "\033[0;32mokay.\033[0m\n"
 fi
 
-printf "=> Checking license headers... "
+printf "=> Checking format... "
+FIRST_OUT="$(git status --porcelain)"
+swiftformat . > /dev/null 2>&1
+SECOND_OUT="$(git status --porcelain)"
+if [[ "$FIRST_OUT" != "$SECOND_OUT" ]]; then
+  printf "\033[0;31mformatting issues!\033[0m\n"
+  git --no-pager diff
+  exit 1
+else
+  printf "\033[0;32mokay.\033[0m\n"
+fi
+
+printf "=> Checking license headers\n"
 tmp=$(mktemp /tmp/.async-http-client-sanity_XXXXXX)
 
 for language in swift-or-c bash dtrace; do
+  printf "   * $language... "
   declare -a matching_files
   declare -a exceptions
   expections=( )