diff --git a/pkgs/by-name/me/merve/package.nix b/pkgs/by-name/me/merve/package.nix
index e8a210d551e6..066ac8fd351d 100644
--- a/pkgs/by-name/me/merve/package.nix
+++ b/pkgs/by-name/me/merve/package.nix
@@ -26,16 +26,14 @@ stdenv.mkDerivation (finalAttrs: {
   cmakeFlags = [
     (lib.cmakeBool "BUILD_SHARED_LIBS" (!static))
     (lib.cmakeBool "MERVE_TESTING" finalAttrs.finalPackage.doCheck)
-    (lib.cmakeBool "MERVE_USE_SIMDUTF" true)
-  ];
+  ]
+  ++ lib.optional (simdutf != null) (lib.cmakeBool "MERVE_USE_SIMDUTF" true);
 
   nativeBuildInputs = [
     cmake
     validatePkgConfig
   ];
-  buildInputs = [
-    simdutf
-  ];
+  buildInputs = lib.optional (simdutf != null) simdutf;
   checkInputs = [
     gtest
   ];
diff --git a/pkgs/development/web/nodejs/nodejs.nix b/pkgs/development/web/nodejs/nodejs.nix
index 537ea51b87cf..10e5d65bf58f 100644
--- a/pkgs/development/web/nodejs/nodejs.nix
+++ b/pkgs/development/web/nodejs/nodejs.nix
@@ -144,7 +144,7 @@ let
   );
   useSharedNBytes = lib.versionAtLeast version (if majorVersion == "24" then "24.14.0" else "25.5");
   useSharedLief = lib.versionAtLeast version "25.6";
-  useSharedMerve = lib.versionAtLeast version (if majorVersion == 24 then "24.14.0" else "25.6.1");
+  useSharedMerve = lib.versionAtLeast version (if majorVersion == "24" then "24.14.0" else "25.6.1");
   useSharedSQLite = lib.versionAtLeast version "22.5";
   useSharedTemporal = majorVersion == "26";
   useSharedZstd = lib.versionAtLeast version "22.15";
@@ -190,7 +190,8 @@ let
     inherit nbytes;
   })
   // (lib.optionalAttrs useSharedMerve {
-    inherit merve;
+    # Merve cannot be built with simdutf_6, and upstream also disables simdutf support on the 24.x branch
+    merve = if majorVersion == "24" then (merve.override { simdutf = null; }) else merve;
   })
   // (lib.optionalAttrs useSharedZstd {
     inherit zstd;