diff --git a/.travis.yml b/.travis.yml
index 669ec731..f105323e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -53,12 +53,12 @@ jobs:
 
   # Test supported versions of Coq via OPAM
   - env:
-    - COQ_IMAGE=coqorg/coq:8.12-ocaml-4.12-flambda
+    - COQ_IMAGE=coqorg/coq:8.12-ocaml-4.11-flambda
     - PACKAGE=coq-hammer.1.3.2+8.12
     - NJOBS=2
     <<: *OPAM
   - env:
-    - COQ_IMAGE=coqorg/coq:8.12-ocaml-4.12-flambda
+    - COQ_IMAGE=coqorg/coq:8.12-ocaml-4.11-flambda
     - PACKAGE=coq-hammer-tactics.1.3.2+8.12
     - NJOBS=2
     <<: *OPAM