diff --git a/requirements.txt b/requirements.txt
index a6902dd2d88736406f611ddf5d76b324987f5dcb..9ee8ba2753febabf337a063f2d082ab10e106ad4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 numpy
 git+git://github.com/inducer/modepy
-git+git://github.com/pyopencl/pyopencl
+git+git://github.com/pyopencl/pyopencl@cffi
+git+git://github.com/inducer/islpy
 git+git://github.com/inducer/loopy
 
 # required by pytential, which is in turn needed for some tests