diff --git a/pkgs/development/compilers/sbcl/default.nix b/pkgs/development/compilers/sbcl/default.nix
index e6724a19d3b2..b50928ce05f3 100644
--- a/pkgs/development/compilers/sbcl/default.nix
+++ b/pkgs/development/compilers/sbcl/default.nix
@@ -10,15 +10,18 @@
 
 let
   versionMap = {
+    # Necessary for Nyxt
     "2.4.6" = {
       sha256 = "sha256-pImQeELa4JoXJtYphb96VmcKrqLz7KH7cCO8pnw/MJE=";
     };
-    "2.4.7" = {
-      sha256 = "sha256-aFRNJQNjWs0BXVNMzJsq6faJltQptakGP9Iv8JJQEdI=";
-    };
+    # By unofficial and very loose convention we keep the latest version of
+    # SBCL, and the previous one in case someone quickly needs to roll back.
     "2.4.8" = {
       sha256 = "sha256-/G7NzFOOgKFKmY1TDMw4SkF5D09Pxs1//oyxJqZ3aUw=";
     };
+    "2.4.9" = {
+      sha256 = "sha256-mXDk68XWlD3GTXyh9S2bXNn8lM75TSMyE9eOx182BeI=";
+    };
   };
   # Collection of pre-built SBCL binaries for platforms that need them for
   # bootstrapping. Ideally these are to be avoided.  If ECL (or any other
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 1b8abbdc9443..27a529704137 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -24163,17 +24163,17 @@ with pkgs;
     faslExt = "fasl";
     flags = [ "--dynamic-space-size" "3000" ];
   };
-  sbcl_2_4_7 = wrapLisp {
-    pkg = callPackage ../development/compilers/sbcl { version = "2.4.7"; };
-    faslExt = "fasl";
-    flags = [ "--dynamic-space-size" "3000" ];
-  };
   sbcl_2_4_8 = wrapLisp {
     pkg = callPackage ../development/compilers/sbcl { version = "2.4.8"; };
     faslExt = "fasl";
     flags = [ "--dynamic-space-size" "3000" ];
   };
-  sbcl = sbcl_2_4_8;
+  sbcl_2_4_9 = wrapLisp {
+    pkg = callPackage ../development/compilers/sbcl { version = "2.4.9"; };
+    faslExt = "fasl";
+    flags = [ "--dynamic-space-size" "3000" ];
+  };
+  sbcl = sbcl_2_4_9;
 
   sbclPackages = recurseIntoAttrs sbcl.pkgs;