diff --git a/.travis.yml b/.travis.yml
index 4643ef3..d0f8030 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -34,7 +34,7 @@ before_install:
 - ping -c2 trough
 
 install:
-- pip install . pytest requests warcio mock
+- pip install .[trough] pytest requests warcio mock
 
 before_script:
 - docker exec trough bash -c 'while ! test -e /tmp/trough-read.out ; do sleep 0.5 ; done' || true
diff --git a/setup.py b/setup.py
index 96089bb..c8306b8 100755
--- a/setup.py
+++ b/setup.py
@@ -28,7 +28,7 @@ deps = [
     'warctools>=4.10.0',
     'urlcanon>=0.3.0',
     'doublethink>=0.2.0.dev87',
-    'urllib3>=1.14',
+    'urllib3>=1.23',
     'requests>=2.0.1',
     'PySocks>=1.6.8',
     'cryptography>=2.3',
diff --git a/warcprox/mitmproxy.py b/warcprox/mitmproxy.py
index 78d0ec3..4b0138e 100644
--- a/warcprox/mitmproxy.py
+++ b/warcprox/mitmproxy.py
@@ -649,13 +649,17 @@ class PooledMixIn(socketserver.ThreadingMixIn):
 
     def process_request(self, request, client_address):
         self.active_requests[request] = doublethink.utcnow()
-        future = self.pool.submit(
-                self.process_request_thread, request, client_address)
-        future.add_done_callback(
-                lambda f: self.active_requests.pop(request, None))
-        if future.done():
-            # avoid theoretical timing issue, in case process_request_thread
-            # managed to finish before future.add_done_callback() ran
+        try:
+            future = self.pool.submit(
+                    self.process_request_thread, request, client_address)
+            future.add_done_callback(
+                    lambda f: self.active_requests.pop(request, None))
+            if future.done():
+                # avoid theoretical timing issue, in case process_request_thread
+                # managed to finish before future.add_done_callback() ran
+                self.active_requests.pop(request, None)
+        except RuntimeError as exc:
+            self.logger.error("Error processing request %s", str(exc))
             self.active_requests.pop(request, None)
 
     def get_request(self):