diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index fb0c9775fc3ec3b5b145036d24090e2cfb20ee85..95e7913279fc7fa5410f355c2a1d30f96e4c11b1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -60,14 +60,14 @@ build-coq.8.7.dev:
 build-coq.8.7.0:
   <<: *template
   variables:
-    OPAM_PINS: "coq version 8.7.0   coq-mathcomp-ssreflect version 1.6.2"
+    OPAM_PINS: "coq version 8.7.0   coq-mathcomp-ssreflect version 1.6.4"
   except:
   - triggers
 
 build-coq.8.6.1:
   <<: *template
   variables:
-    OPAM_PINS: "coq version 8.6.1   coq-mathcomp-ssreflect version 1.6.2"
+    OPAM_PINS: "coq version 8.6.1   coq-mathcomp-ssreflect version 1.6.4"
     VALIDATE: "1"
   artifacts:
     paths:
diff --git a/README.md b/README.md
index ff5fba87fe72889aa00617fbeefb3c1ca0623103..1cfec97a868839746efe746d895bd84c7bba8160 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ This is the Coq development of the [Iris Project](http://iris-project.org).
 This version is known to compile with:
 
  - Coq 8.6.1 / 8.7.0
- - Ssreflect 1.6.2
+ - Ssreflect 1.6.4
  - A development version of [std++](https://gitlab.mpi-sws.org/robbertkrebbers/coq-stdpp)
 
 If you need to work with Coq 8.5, please check out the