diff --git a/spack.yaml b/spack.yaml
index 3cc7c30d42f2aa6ad64346c5d7ddb73b4162a13c..c3e80f97f08b392fe2b3a0996834f4404b6556a7 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -1,7 +1,7 @@
 spack:
   specs:
     # system
-    - autoconf %gcc@10.3.0
+    - autoconf@2.70 %gcc@10.3.0
     # Notebook
     - py-jupyter %gcc@10.3.0
     - py-ipython %gcc@10.3.0