diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 4bd829b..ec6c2f2 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -42,6 +42,8 @@ end)
 describe('selene', function()
   it('can lint', function()
     -- pre-test setup
+    local helper = require('test.linter.helper')
+    local ns = helper.namespace
     local ft = require('guard.filetype')
     ft('lua'):lint('selene')
     require('guard').setup()
@@ -65,7 +67,8 @@ describe('selene', function()
         end_lnum = 4,
         lnum = 4,
         message = '`U` is not defined [undefined_variable]',
-        namespace = 4,
+        -- sometimes the namespace is not fixed
+        namespace = ns,
         severity = 1,
         source = 'selene',
       },
diff --git a/test/linter/clang-tidy_spec.lua b/test/linter/clang-tidy_spec.lua
index 19656f7..6e49502 100644
--- a/test/linter/clang-tidy_spec.lua
+++ b/test/linter/clang-tidy_spec.lua
@@ -1,10 +1,12 @@
 describe('clang-tidy', function()
   it('can lint', function()
+    local helper = require('test.linter.helper')
+    local ns = helper.namespace
     local ft = require('guard.filetype')
     ft('c'):lint('clang-tidy')
     require('guard').setup()
 
-    local diagnostics = require('test.linter.helper').test_with('c', {
+    local diagnostics = helper.test_with('c', {
       [[#include <stdio.h>]],
       [[int main() {]],
       [[    int x = 10;]],
@@ -22,7 +24,7 @@ describe('clang-tidy', function()
         end_lnum = 4,
         lnum = 4,
         message = 'Division by zero [clang-analyzer-core.DivideZero]',
-        namespace = 1,
+        namespace = ns,
         severity = 2,
         source = 'clang-tidy',
       },
diff --git a/test/linter/flake8_spec.lua b/test/linter/flake8_spec.lua
index a4cf44c..c62f40c 100644
--- a/test/linter/flake8_spec.lua
+++ b/test/linter/flake8_spec.lua
@@ -1,10 +1,12 @@
 describe('flake8', function()
   it('can lint', function()
+    local helper = require('test.linter.helper')
+    local ns = helper.namespace
     local ft = require('guard.filetype')
     ft('python'):lint('flake8')
     require('guard').setup()
 
-    local diagnostics = require('test.linter.helper').test_with('python', {
+    local diagnostics = helper.test_with('python', {
       [[import os]],
       [[]],
       [[def foo(n):]],
@@ -20,7 +22,7 @@ describe('flake8', function()
         end_lnum = 0,
         lnum = 0,
         message = "'os' imported but unused [401]",
-        namespace = 1,
+        namespace = ns,
         severity = 3,
         source = 'flake8',
       },
@@ -31,7 +33,7 @@ describe('flake8', function()
         end_lnum = 2,
         lnum = 2,
         message = 'expected 2 blank lines, found 1 [302]',
-        namespace = 1,
+        namespace = ns,
         severity = 1,
         source = 'flake8',
       },
@@ -42,7 +44,7 @@ describe('flake8', function()
         end_lnum = 4,
         lnum = 4,
         message = 'indentation is not a multiple of 4 [111]',
-        namespace = 1,
+        namespace = ns,
         severity = 1,
         source = 'flake8',
       },
@@ -53,7 +55,7 @@ describe('flake8', function()
         end_lnum = 4,
         lnum = 4,
         message = 'over-indented [117]',
-        namespace = 1,
+        namespace = ns,
         severity = 1,
         source = 'flake8',
       },
@@ -64,7 +66,7 @@ describe('flake8', function()
         end_lnum = 4,
         lnum = 4,
         message = 'multiple spaces after keyword [271]',
-        namespace = 1,
+        namespace = ns,
         severity = 1,
         source = 'flake8',
       },
@@ -75,7 +77,7 @@ describe('flake8', function()
         end_lnum = 4,
         lnum = 4,
         message = "undefined name 'bar' [821]",
-        namespace = 1,
+        namespace = ns,
         severity = 3,
         source = 'flake8',
       },
@@ -86,7 +88,7 @@ describe('flake8', function()
         end_lnum = 5,
         lnum = 5,
         message = 'expected 2 blank lines after class or function definition, found 0 [305]',
-        namespace = 1,
+        namespace = ns,
         severity = 1,
         source = 'flake8',
       },
@@ -97,7 +99,7 @@ describe('flake8', function()
         end_lnum = 5,
         lnum = 5,
         message = 'line too long (80 > 79 characters) [501]',
-        namespace = 1,
+        namespace = ns,
         severity = 1,
         source = 'flake8',
       },
diff --git a/test/linter/hadolint_spec.lua b/test/linter/hadolint_spec.lua
index 8492185..0f54d25 100644
--- a/test/linter/hadolint_spec.lua
+++ b/test/linter/hadolint_spec.lua
@@ -1,10 +1,12 @@
 describe('hadolint', function()
   it('can lint', function()
+    local helper = require('test.linter.helper')
+    local ns = helper.namespace
     local ft = require('guard.filetype')
     ft('dockerfile'):lint('hadolint')
     require('guard').setup()
 
-    local diagnostics = require('test.linter.helper').test_with('dockerfile', {
+    local diagnostics = helper.test_with('dockerfile', {
       [[FROM alpine:3.18]],
       [[RUN {{Definitely not valid bash]],
       [[COPY foo bar]],
@@ -19,7 +21,7 @@ describe('hadolint', function()
         end_lnum = 1,
         lnum = 1,
         message = "Missing '}'. Fix any mentioned problems and try again. [SC1072]",
-        namespace = 4,
+        namespace = ns,
         severity = 1,
         source = 'hadolint',
       },
@@ -30,7 +32,7 @@ describe('hadolint', function()
         end_lnum = 2,
         lnum = 2,
         message = '`COPY` to a relative destination without `WORKDIR` set. [DL3045]',
-        namespace = 4,
+        namespace = ns,
         severity = 2,
         source = 'hadolint',
       },
diff --git a/test/linter/helper.lua b/test/linter/helper.lua
index 928cb1a..d3c1570 100644
--- a/test/linter/helper.lua
+++ b/test/linter/helper.lua
@@ -1,5 +1,6 @@
 local M = {}
 local api = vim.api
+M.namespace = api.nvim_get_namespaces().Guard
 
 function M.test_with(ft, input)
   local bufnr = api.nvim_create_buf(true, false)
diff --git a/test/linter/luacheck_spec.lua b/test/linter/luacheck_spec.lua
index 3af7637..9f18b38 100644
--- a/test/linter/luacheck_spec.lua
+++ b/test/linter/luacheck_spec.lua
@@ -1,10 +1,12 @@
 describe('luacheck', function()
   it('can lint', function()
+    local helper = require('test.linter.helper')
+    local ns = helper.namespace
     local ft = require('guard.filetype')
     ft('lua'):lint('luacheck')
     require('guard').setup()
 
-    local diagnostics = require('test.linter.helper').test_with('lua', {
+    local diagnostics = helper.test_with('lua', {
       [[local M = {}]],
       [[function M.foo()]],
       [[  print("foo")]],
@@ -20,7 +22,7 @@ describe('luacheck', function()
         end_lnum = 4,
         lnum = 4,
         message = "accessing undefined variable 'U' [113]",
-        namespace = 4,
+        namespace = ns,
         severity = 2,
         source = 'luacheck',
       },
diff --git a/test/linter/pylint_spec.lua b/test/linter/pylint_spec.lua
index cc45bb0..7d4fa59 100644
--- a/test/linter/pylint_spec.lua
+++ b/test/linter/pylint_spec.lua
@@ -1,10 +1,12 @@
 describe('pylint', function()
   it('can lint', function()
+    local helper = require('test.linter.helper')
+    local ns = helper.namespace
     local ft = require('guard.filetype')
     ft('python'):lint('pylint')
     require('guard').setup()
 
-    local diagnostics = require('test.linter.helper').test_with('python', {
+    local diagnostics = helper.test_with('python', {
       [[def foo(n):]],
       [[    if n in (1, 2, 3):]],
       [[        return n + 1]],
@@ -20,7 +22,7 @@ describe('pylint', function()
         end_lnum = 0,
         lnum = 0,
         message = 'Missing module docstring [missing-module-docstring]',
-        namespace = 4,
+        namespace = ns,
         severity = 3,
         source = 'pylint',
       },
@@ -31,7 +33,7 @@ describe('pylint', function()
         end_lnum = 0,
         lnum = 0,
         message = 'Missing function or method docstring [missing-function-docstring]',
-        namespace = 4,
+        namespace = ns,
         severity = 3,
         source = 'pylint',
       },
@@ -42,7 +44,7 @@ describe('pylint', function()
         end_lnum = 0,
         lnum = 0,
         message = 'Disallowed name "foo" [disallowed-name]',
-        namespace = 4,
+        namespace = ns,
         severity = 3,
         source = 'pylint',
       },
@@ -53,7 +55,7 @@ describe('pylint', function()
         end_lnum = 0,
         lnum = 0,
         message = 'Argument name "n" doesn\'t conform to snake_case naming style [invalid-name]',
-        namespace = 4,
+        namespace = ns,
         severity = 3,
         source = 'pylint',
       },
@@ -64,7 +66,7 @@ describe('pylint', function()
         end_lnum = 0,
         lnum = 0,
         message = 'Either all return statements in a function should return an expression, or none of them should. [inconsistent-return-statements]',
-        namespace = 4,
+        namespace = ns,
         severity = 3,
         source = 'pylint',
       },
diff --git a/test/linter/selene_spec.lua b/test/linter/selene_spec.lua
index eea5243..345bb80 100644
--- a/test/linter/selene_spec.lua
+++ b/test/linter/selene_spec.lua
@@ -1,10 +1,12 @@
 describe('selene', function()
   it('can lint', function()
+    local helper = require('test.linter.helper')
+    local ns = helper.namespace
     local ft = require('guard.filetype')
     ft('lua'):lint('selene')
     require('guard').setup()
 
-    local diagnostics = require('test.linter.helper').test_with('lua', {
+    local diagnostics = helper.test_with('lua', {
       [[local M = {}]],
       [[function M.foo()]],
       [[  print("foo")]],
@@ -20,7 +22,7 @@ describe('selene', function()
         end_lnum = 4,
         lnum = 4,
         message = '`U` is not defined [undefined_variable]',
-        namespace = 4,
+        namespace = ns,
         severity = 1,
         source = 'selene',
       },