diff --git a/default.nix b/default.nix
index 079f7db..2a91a4e 100644
--- a/default.nix
+++ b/default.nix
@@ -77,7 +77,7 @@ in
   // (
     if pkgs.system == "riscv64-linux"
     then {
-      inherit (pkgsWithOverlay) vf2Kernel;
+      inherit (pkgsWithOverlay) vf2Kernel valgrind;
     }
     else {}
   )
diff --git a/flake.nix b/flake.nix
index da49f2c..e8e9001 100644
--- a/flake.nix
+++ b/flake.nix
@@ -121,7 +121,7 @@
           // (
             if system == "riscv64-linux"
             then {
-              inherit (pkgs) vf2Kernel;
+              inherit (pkgs) vf2Kernel valgrind;
             }
             else {}
           )
diff --git a/overlay.nix b/overlay.nix
index 03039ea..1c3cd22 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -32,16 +32,23 @@ system: self: super: let
         });
         libopus = super.libopus.overrideAttrs (_: {
           mesonFlags = [
-            (lib.mesonBool "fixed-point" false)
-            (lib.mesonBool "custom-modes" true)
-            (lib.mesonEnable "intrinsics" false)
-            (lib.mesonEnable "rtcd" false)
-            (lib.mesonEnable "asm" false)
-            (lib.mesonEnable "docs" false)
+            "-Dfixed-point=false"
+            "-Dcustom-modes=true"
+            "-Dintrinsics=disabled"
+            "-Drtcd=disabled"
+            "-Dasm=disabled"
+            "-Dasm=disabled"
+            "-Ddocs=disabled"
           ];
           doCheck = false;
           doInstallCheck = false;
         });
+        valgrind = self.callPackage ./riscv/valgrind {};
+        valgrind-light = self.valgrind;
+        openldap = super.openldap.overrideAttrs (_: {
+          doCheck = false;
+          doInstallCheck = false;
+        });
       })
     else (_: _: {});
 
diff --git a/riscv/valgrind/default.nix b/riscv/valgrind/default.nix
new file mode 100644
index 0000000..74020e4
--- /dev/null
+++ b/riscv/valgrind/default.nix
@@ -0,0 +1,82 @@
+{
+  lib,
+  stdenv,
+  fetchFromGitHub,
+  perl,
+  gdb,
+  autoreconfHook,
+}: let
+  source = builtins.fromJSON (builtins.readFile ./source.json);
+in
+  stdenv.mkDerivation rec {
+    pname = "valgrind-riscv64";
+    version = source.date;
+
+    src = fetchFromGitHub {
+      owner = "petrpavlu";
+      repo = "valgrind-riscv64";
+      inherit (source) rev sha256;
+    };
+
+    outputs = ["out" "dev"];
+
+    hardeningDisable = ["stackprotector"];
+
+    # GDB is needed to provide a sane default for `--db-command'.
+    # Perl is needed for `callgrind_{annotate,control}'.
+    buildInputs = [gdb perl];
+
+    # Perl is also a native build input.
+    nativeBuildInputs = [autoreconfHook perl];
+
+    enableParallelBuilding = true;
+    separateDebugInfo = stdenv.isLinux;
+
+    # To prevent rebuild on linux when moving darwin's postPatch fixes to preConfigure
+    postPatch = "";
+
+    doCheck = true;
+
+    postInstall = ''
+      for i in $out/libexec/valgrind/*.supp; do
+        substituteInPlace $i \
+          --replace 'obj:/lib' 'obj:*/lib' \
+          --replace 'obj:/usr/X11R6/lib' 'obj:*/lib' \
+          --replace 'obj:/usr/lib' 'obj:*/lib'
+      done
+    '';
+
+    passthru.updateScript = [
+      ../../scripts/update-git.sh
+      "https://github.com/petrpavlu/valgrind-riscv64"
+      "riscv/valgrind/source.json"
+    ];
+
+    meta = {
+      homepage = "http://www.valgrind.org/";
+      description = "Debugging and profiling tool suite";
+
+      longDescription = ''
+        Valgrind is an award-winning instrumentation framework for
+        building dynamic analysis tools.  There are Valgrind tools that
+        can automatically detect many memory management and threading
+        bugs, and profile your programs in detail.  You can also use
+        Valgrind to build new tools.
+      '';
+
+      license = lib.licenses.gpl2Plus;
+
+      maintainers = [lib.maintainers.nickcao];
+      platforms = lib.platforms.unix;
+      badPlatforms = [
+        "armv5tel-linux"
+        "armv6l-linux"
+        "armv6m-linux"
+        "sparc-linux"
+        "sparc64-linux"
+        "riscv32-linux"
+        "alpha-linux"
+      ];
+      broken = stdenv.isDarwin || stdenv.hostPlatform.isStatic; # https://hydra.nixos.org/build/128521440/nixlog/2
+    };
+  }
diff --git a/riscv/valgrind/source.json b/riscv/valgrind/source.json
new file mode 100644
index 0000000..bfc9dd9
--- /dev/null
+++ b/riscv/valgrind/source.json
@@ -0,0 +1,11 @@
+{
+  "url": "https://github.com/petrpavlu/valgrind-riscv64",
+  "rev": "71272b252977fe52f03ea4fa8306b457b098cca5",
+  "date": "2023-04-10T20:43:50+02:00",
+  "path": "/nix/store/g00qg2qhm10c0a6v5v7al89pc57b4bjy-valgrind-riscv64",
+  "sha256": "0znk98hypdh7j84h237131aqsczz91mrwpwkvy1xgaxkhiskhgy4",
+  "fetchLFS": false,
+  "fetchSubmodules": false,
+  "deepClone": false,
+  "leaveDotGit": false
+}