diff --git a/pkgs/quicly/default.nix b/pkgs/quicly/default.nix
index 9ab945c..9f3f184 100644
--- a/pkgs/quicly/default.nix
+++ b/pkgs/quicly/default.nix
@@ -2,17 +2,11 @@
 , cmake
 , openssl
 , perl
+, picotls
 , fetchFromGitHub
 }:
 
 let
-  picotls = fetchFromGitHub {
-    owner = "h2o";
-    repo = "picotls";
-    rev = "9238121fa7788e8642072b6d4d1a2f2fb71db242";
-    sha256 = "0yam62yd606q8v515r74l110gmch4i4bif9hfxn7mgvcdv979l7d";
-  };
-
   picotest = fetchFromGitHub {
     owner = "h2o";
     repo = "picotest";
@@ -50,11 +44,11 @@ stdenv.mkDerivation rec {
   ];
 
   patchPhase = ''
-    sed -i 's|''${CMAKE_SOURCE_DIR}/deps/picotls|${picotls}|g' CMakeLists.txt
+    sed -i 's|''${CMAKE_SOURCE_DIR}/deps/picotls|${picotls.src}|g' CMakeLists.txt
     sed -i 's|deps/klib|${klib}|g' CMakeLists.txt
-    sed -i 's|deps/picotls|${picotls}|g' CMakeLists.txt
+    sed -i 's|deps/picotls|${picotls.src}|g' CMakeLists.txt
     sed -i 's|deps/picotest|${picotest}|g' CMakeLists.txt
-    sed -i 's|\.\./deps/picotls|${picotls}|g' src/cli.c
+    sed -i 's|../deps/picotls|${picotls.src}|g' src/cli.c
   '';
 
   installPhase = ''