diff --git a/README.md b/README.md
index e18c05c..f634582 100644
--- a/README.md
+++ b/README.md
@@ -69,8 +69,6 @@ as XSane or simple-scan should be able to scan from them.
 eSCL support in Windows has been introduced in Windows 11 first, but is now available
 in Windows 10 as well: <https://support.microsoft.com/en-us/topic/june-28-2022-kb5014666-os-builds-19042-1806-19043-1806-and-19044-1806-preview-4bd911df-f290-4753-bdec-a83bc8709eb6>
 
-Unfortunately, eSCL scanning from Windows seems to be broken as of Nov. 2023.
-
 #### Connecting to an AirSane scanner
 Go to "Settings"->"Bluetooth & devices"->"Printers and Scanners."
 There, click "Add Device".
diff --git a/web/httpserver.cpp b/web/httpserver.cpp
index 1628b1f..e86c143 100644
--- a/web/httpserver.cpp
+++ b/web/httpserver.cpp
@@ -23,6 +23,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <ctime>
 #include <sstream>
 #include <thread>
+#include <mutex>
 
 #include <arpa/inet.h>
 #ifdef __FreeBSD__
@@ -200,6 +201,7 @@ struct HttpServer::Private
   std::string mInterfaceName, mUnixSocket;
   int mInterfaceIndex, mBacklog;
   AccessFile mAccessFile;
+  std::mutex mAccessFileMutex;
 
   std::atomic<bool> mRunning;
   std::atomic<int> mPipeWriteFd;
@@ -374,10 +376,12 @@ struct HttpServer::Private
 
   void handleRequest(int fd, Sockaddr address)
   {
+    std::unique_lock<std::mutex> lock(mAccessFileMutex);
     if (!mAccessFile.isAllowed(address)) {
       ::close(fd);
       return;
     }
+    lock.unlock();
 
     fdbuf buf(fd);
     std::istream is(&buf);
@@ -562,6 +566,7 @@ HttpServer::backlog() const
 HttpServer&
 HttpServer::applyAccessFile(const AccessFile& file)
 {
+  std::lock_guard<std::mutex> lock(p->mAccessFileMutex);
   p->mAccessFile = file;
   return *this;
 }