diff --git a/pkgs/development/coq-modules/coquelicot/default.nix b/pkgs/development/coq-modules/coquelicot/default.nix
index 680e154de68a..806d7d1304b9 100644
--- a/pkgs/development/coq-modules/coquelicot/default.nix
+++ b/pkgs/development/coq-modules/coquelicot/default.nix
@@ -15,6 +15,10 @@ mkCoqDerivation {
   defaultVersion =
     with lib.versions;
     lib.switch coq.coq-version [
+      {
+        case = range "8.12" "9.0";
+        out = "3.4.3";
+      }
       {
         case = range "8.12" "8.20";
         out = "3.4.2";
@@ -40,6 +44,7 @@ mkCoqDerivation {
         out = "3.0.2";
       }
     ] null;
+  release."3.4.3".sha256 = "sha256-bzzAIENU2OYTtmdBU9Xw8zyBvz9vqTiqjWSm7RnXXRA=";
   release."3.4.2".sha256 = "sha256-aBTF8ZKu67Rb3ryCqFyejUXf/65KgG8i5je/ZMFSrj4=";
   release."3.4.1".sha256 = "sha256-REhvIBl3EaL8CQqI34Gn7Xjf9NhPI3nrUAO26pSLbm0=";
   release."3.4.0".sha256 = "sha256-LIj2SwTvVBxSAO58VYCQix/uxQQe8ey6hqFOSh3PNcg=";