diff --git a/lune/ensure-tests.luau b/lune/ensure-tests.luau
new file mode 100644
index 0000000..9a90873
--- /dev/null
+++ b/lune/ensure-tests.luau
@@ -0,0 +1,78 @@
+local fs = require("@lune/fs")
+local process = require("@lune/process")
+
+local crayon = require("./lib/crayon")
+
+local cwd = process.cwd:gsub("\\", "/"):gsub("/$", "")
+local src = `{cwd}/src`
+local tests = `{src}/__tests__`
+
+local IGNORED_FILES = {
+    `{src}/Array/init.luau`,
+    `{src}/Dictionary/init.luau`,
+    `{src}/Set/init.luau`,
+    `{src}/init.luau`,
+    `{src}/None.luau`,
+    `{src}/Util.luau`,
+}
+
+local function get_file_paths(root: string)
+    local paths = {}
+
+    for _, path in fs.readDir(root) do
+        local fullPath = `{root}/{path}`
+
+        if fs.isFile(fullPath) then
+            table.insert(paths, fullPath)
+            continue
+        end
+
+        if fs.isDir(fullPath) and fullPath == tests then
+            continue
+        end
+
+        for _, subpath in get_file_paths(fullPath) do
+            table.insert(paths, subpath)
+        end
+    end
+
+    return paths
+end
+
+local function main()
+    local files = get_file_paths(src)
+    local missing = 0
+
+    for _, file in files do
+        if not file:match("%.luau$") or table.find(IGNORED_FILES, file) then
+            continue
+        end
+
+        local relativePath = file:sub(#src + 2)
+        local testFilePath = (`{tests}/{relativePath}`):gsub("%.luau$", ".spec.luau")
+
+        if not fs.isFile(testFilePath) then
+            print(
+                crayon.label("MISSING", crayon.bgRed),
+                "No test found for",
+                crayon.yellow(`"./{relativePath}"`)
+            )
+
+            missing += 1
+            continue
+        end
+    end
+
+    if missing > 0 then
+        print(
+            crayon.label("FAIL", crayon.bgRed),
+            "Missing",
+            crayon.bold(tostring(missing)),
+            "test files."
+        )
+
+        process.exit(1)
+    end
+end
+
+main()