diff --git a/build.zig b/build.zig
index 8b43b13fbb..07c14060c2 100644
--- a/build.zig
+++ b/build.zig
@@ -44,9 +44,10 @@ pub fn build(b: *std.Build) !void {
 
     const cc = b.option([]const u8, "cc", "C compiler") orelse "zig";
     const no_exec = b.option(bool, "no-exec", "Compile test binary without running it") orelse false;
+    const valgrind = b.option(bool, "valgrind", "Run tests under valgrind") orelse false;
 
     const test_step = b.step("test", "Run unit tests");
-    addTestStep(b, test_step, target, optimize, cc, no_exec);
+    addTestStep(b, test_step, target, optimize, cc, no_exec, valgrind);
 
     const fmt_step = b.step("fmt", "clang-format");
     const clang_format = b.addSystemCommand(&.{ "clang-format", "-i" });
@@ -102,7 +103,7 @@ pub fn build(b: *std.Build) !void {
     all_step.dependOn(&fmt_check.step);
 
     for (compilers) |compiler| {
-        addTestStep(b, all_step, target, optimize, compiler, false);
+        addTestStep(b, all_step, target, optimize, compiler, false, valgrind);
     }
 
     b.default_step = all_step;
@@ -115,6 +116,7 @@ fn addTestStep(
     optimize: std.builtin.OptimizeMode,
     cc: []const u8,
     no_exec: bool,
+    valgrind: bool,
 ) void {
     const test_mod = b.createModule(.{
         .root_source_file = b.path("test_all.zig"),
@@ -144,6 +146,17 @@ fn addTestStep(
     }
 
     const test_exe = b.addTest(.{ .root_module = test_mod });
+    if (valgrind) {
+        test_exe.setExecCmd(&.{
+            "valgrind",
+            "--error-exitcode=2",
+            "--leak-check=full",
+            "--show-leak-kinds=all",
+            "--errors-for-leak-kinds=all",
+            "--track-fds=yes",
+            null,
+        });
+    }
     if (no_exec) {
         const install = b.addInstallArtifact(test_exe, .{});
         step.dependOn(&install.step);