diff --git a/requirements.txt b/requirements.txt
index abe39e8935e461184ed65898c568e8697162594b..8d1d17faa66e8a997f5de91af2cdf247ee0797d8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,6 @@
 numpy
 sympy==1.0
+git+https://github.com/pyopencl/pymbolic
 git+https://github.com/inducer/islpy
 git+https://github.com/pyopencl/pyopencl
 git+https://github.com/inducer/boxtree