diff --git a/var/spack/repos/builtin/packages/py-astropy/package.py b/var/spack/repos/builtin/packages/py-astropy/package.py
index cd2bcb1c707..adbc56cada4 100644
--- a/var/spack/repos/builtin/packages/py-astropy/package.py
+++ b/var/spack/repos/builtin/packages/py-astropy/package.py
@@ -62,7 +62,7 @@ class PyAstropy(PythonPackage):
     # System dependencies
     depends_on('erfa')
     depends_on('wcslib')
-    depends_on('cfitsio')
+    depends_on('cfitsio@:3')
     depends_on('expat')
 
     def patch(self):