diff --git a/Makefile b/Makefile
index 14f545c..b0a248b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,15 @@
 all: test check
 
-test:
-	nvim --headless --noplugin -u tests/minimal.vim +Test
+install_plenary:
+	if [ ! -d ~/.local/share/nvim/site/pack/vendor/opt/plenary.nvim ]; \
+	then \
+		git clone --depth 1 https://github.com/nvim-lua/plenary.nvim \
+		~/.local/share/nvim/site/pack/vendor/opt/plenary.nvim; \
+	fi
+
+test: install_plenary
+	nvim --headless --noplugin -u tests/minimal.vim -R \
+		-c "PlenaryBustedDirectory tests/ {minimal_init = 'tests/minimal.vim'}"
 
 check:
 	stylua --color always --check .
diff --git a/tests/heuristic_spec.lua b/tests/heuristic_spec.lua
new file mode 100644
index 0000000..d2276e4
--- /dev/null
+++ b/tests/heuristic_spec.lua
@@ -0,0 +1,36 @@
+local gi = require("guess-indent")
+local t = require("plenary.async.tests")
+
+local test_cases = require("tests.utils").load_test_cases()
+
+-- Check that all files indentation gets detected correctly.
+t.describe("guess-indent", function()
+  for lang, tc in pairs(test_cases) do
+    t.describe("for " .. lang, function()
+      for _, file in ipairs(tc) do
+        -- Open a new buffer containing the file
+        vim.cmd(":edit! " .. file.path)
+
+        -- Get first line from buffer and try to extract the expectation
+        local line = vim.api.nvim_buf_get_lines(0, 0, 1, false)
+        local data = loadstring("return " .. line[1]:match("{.*}"))()
+        local expectation = data.expected
+
+        if data.disabled then
+          print("WARNING: Skipping test case for file '" .. file.path .. "'")
+          goto cleanup
+        end
+
+        -- Perfom test
+        t.it("should indent: " .. file.name, function()
+          local result = gi.guess_from_buffer()
+          assert.are.equal(expectation, result)
+        end)
+
+        -- Cleanup
+        ::cleanup::
+        print(vim.cmd(":bdelete!"))
+      end
+    end)
+  end
+end)
diff --git a/tests/init_spec.lua b/tests/init_spec.lua
deleted file mode 100644
index cdf9bea..0000000
--- a/tests/init_spec.lua
+++ /dev/null
@@ -1,66 +0,0 @@
-local gi = require("guess-indent")
-
--- LOAD TEST DATA --
-
--- Load all test cases in the data directory
-local test_data_path = "./tests/data/"
-local subfolders = vim.fn.readdir(test_data_path)
-
-local test_cases = {}
-
-for _, language in ipairs(subfolders) do
-  local language_path = test_data_path .. language .. "/"
-  if vim.fn.isdirectory(language_path) ~= 0 then
-    local l_test_cases = {}
-    local test_files = vim.fn.readdir(language_path, "v:val =~ '\\..*$'")
-
-    for i, file_name in ipairs(test_files) do
-      l_test_cases[i] = {
-        path = language_path .. file_name,
-        name = file_name,
-      }
-    end
-
-    test_cases[language] = l_test_cases
-  end
-end
-
------------
--- TESTS --
------------
-
--- Correctness
-describe("guess-indent", function()
-  for lang, tc in pairs(test_cases) do
-    describe("for " .. lang, function()
-      for _, file in ipairs(tc) do
-        -- Open a new buffer containing the file
-        vim.cmd(":edit! " .. file.path)
-
-        -- Get first line from buffer and try to extract the expectation
-        local line = vim.api.nvim_buf_get_lines(0, 0, 1, false)
-        local data = loadstring("return " .. line[1]:match("{.*}"))()
-        local expectation = data.expected
-
-        if data.disabled then
-          print("WARNING: Skipping test case for file '" .. file.path .. "'")
-          goto cleanup
-        end
-
-        -- Perfom test
-        it("should indent: " .. file.name, function()
-          local result = gi.guess_from_buffer()
-          assert.are.equal(expectation, result)
-        end)
-
-        -- Cleanup
-        ::cleanup::
-        print(vim.cmd(":bdelete!"))
-      end
-    end)
-  end
-end)
-
--- Print newline. Else the the last print statement would not be visible
--- in the output.
-print("\n")
diff --git a/tests/minimal.vim b/tests/minimal.vim
index da1e24a..fdde94c 100644
--- a/tests/minimal.vim
+++ b/tests/minimal.vim
@@ -1,11 +1,7 @@
-if !isdirectory('plenary.nvim')
-  !git clone https://github.com/nvim-lua/plenary.nvim.git plenary.nvim
-  !git -C plenary.nvim reset --hard 1338bbe8ec6503ca1517059c52364ebf95951458
-endif
+packadd plenary.nvim
+runtime plugin/plenary.vim
+
+set rtp+=.
 
-set runtimepath+=plenary.nvim,.
 set noswapfile
 set noundofile
-
-runtime plugin/plenary.vim
-command Test PlenaryBustedDirectory tests/ {minimal_init = 'tests/minimal.vim'} 
diff --git a/tests/utils.lua b/tests/utils.lua
new file mode 100644
index 0000000..222f1e6
--- /dev/null
+++ b/tests/utils.lua
@@ -0,0 +1,30 @@
+local M = {}
+
+-- Load all test cases in the data directory
+function M.load_test_cases()
+  local test_data_path = "./tests/data/"
+  local subfolders = vim.fn.readdir(test_data_path)
+
+  local test_cases = {}
+
+  for _, language in ipairs(subfolders) do
+    local language_path = test_data_path .. language .. "/"
+    if vim.fn.isdirectory(language_path) ~= 0 then
+      local l_test_cases = {}
+      local test_files = vim.fn.readdir(language_path, "v:val !~ '^\\.\\|\\~$'")
+
+      for i, file_name in ipairs(test_files) do
+        l_test_cases[i] = {
+          path = language_path .. file_name,
+          name = file_name,
+        }
+      end
+
+      test_cases[language] = l_test_cases
+    end
+  end
+
+  return test_cases
+end
+
+return M