diff --git a/var/spack/repos/builtin/packages/py-isal/package.py b/var/spack/repos/builtin/packages/py-isal/package.py
index 3a4efa4ef78..c2b134234ef 100644
--- a/var/spack/repos/builtin/packages/py-isal/package.py
+++ b/var/spack/repos/builtin/packages/py-isal/package.py
@@ -19,3 +19,7 @@ class PyIsal(PythonPackage):
 
     depends_on("python@3.7:", type=("build", "run"))
     depends_on("py-setuptools@51:", type="build")
+    depends_on("libisal")
+
+    def setup_build_environment(self, env):
+        env.set("PYTHON_ISAL_LINK_DYNAMIC", "true")