diff --git a/pkgs/servers/sql/mariadb/connector-c/default.nix b/pkgs/servers/sql/mariadb/connector-c/default.nix
index 628bf08c79aa..969cf26b5b4c 100644
--- a/pkgs/servers/sql/mariadb/connector-c/default.nix
+++ b/pkgs/servers/sql/mariadb/connector-c/default.nix
@@ -35,6 +35,13 @@ stdenv.mkDerivation {
       url = "https://github.com/mariadb-corporation/mariadb-connector-c/commit/e8448137f3365568090d5c0d4051039ddc1cdb6f.patch";
       hash = "sha256-aDbaaJA8DxGG5RrOa+CHhk4wuzlBy5tWyS+f/zVYU0c=";
     })
+
+    # Fix the build with CMake 4.
+    (fetchpatch {
+      name = "mariadb-connector-c-fix-cmake-4.patch";
+      url = "https://github.com/mariadb-corporation/mariadb-connector-c/commit/598dc3d2d7a63e5d250421dd0ea88be55ea8511f.patch";
+      hash = "sha256-HojNRobguBmtpEdr2lVi/MpcoDAsZnb3+tw/pt376es=";
+    })
   ];
 
   outputs = [