diff --git a/test-requirements.txt b/test-requirements.txt
index c2024fc02..00fbc8085 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,2 +1,9 @@
+# Remove PIL dependency once a new mitmproxy version is released
+# with bugfix: https://github.com/mitmproxy/mitmproxy/pull/197
+--allow-external PIL
+--allow-unverified PIL
+PIL>=1.1.7
+
+# Tests requirements
 mock
 mitmproxy