diff --git a/src/main/resources/org/eolang/lints/tests/test-word.xsl b/src/main/resources/org/eolang/lints/tests/test-word.xsl
new file mode 100644
index 000000000..80dd521d1
--- /dev/null
+++ b/src/main/resources/org/eolang/lints/tests/test-word.xsl
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+* SPDX-FileCopyrightText: Copyright (c) 2016-2026 Objectionary.com
+* SPDX-License-Identifier: MIT
+-->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:eo="https://www.eolang.org" id="test-word" version="2.0">
+  <xsl:import href="/org/eolang/funcs/lineno.xsl"/>
+  <xsl:import href="/org/eolang/funcs/escape.xsl"/>
+  <xsl:import href="/org/eolang/funcs/test-name.xsl"/>
+  <xsl:import href="/org/eolang/funcs/defect-context.xsl"/>
+  <xsl:output encoding="UTF-8" method="xml"/>
+  <xsl:template match="/">
+    <defects>
+      <xsl:variable name="top" select="/object/o[1]"/>
+      <xsl:for-each select="//o[@name and not(@name='φ') and matches(@name, 'test', 'i') and not(generate-id() = generate-id($top))]">
+        <xsl:if test="eo:test-name(@name) or ancestor::o[eo:test-name(@name)] or matches($top/@name, '-tests$')">
+          <xsl:element name="defect">
+            <xsl:variable name="line" select="eo:lineno(@line)"/>
+            <xsl:attribute name="line">
+              <xsl:value-of select="$line"/>
+            </xsl:attribute>
+            <xsl:if test="$line = '0'">
+              <xsl:attribute name="context">
+                <xsl:value-of select="eo:defect-context(.)"/>
+              </xsl:attribute>
+            </xsl:if>
+            <xsl:attribute name="severity">
+              <xsl:text>warning</xsl:text>
+            </xsl:attribute>
+            <xsl:text>The name of the object </xsl:text>
+            <xsl:value-of select="eo:escape(@name)"/>
+            <xsl:text> must not contain the word 'test'</xsl:text>
+          </xsl:element>
+        </xsl:if>
+      </xsl:for-each>
+    </defects>
+  </xsl:template>
+</xsl:stylesheet>
diff --git a/src/main/resources/org/eolang/motives/tests/test-word.md b/src/main/resources/org/eolang/motives/tests/test-word.md
new file mode 100644
index 000000000..b32615a0c
--- /dev/null
+++ b/src/main/resources/org/eolang/motives/tests/test-word.md
@@ -0,0 +1,26 @@
+# Test word
+
+Names of objects in test files must not contain the word 'test'. If an object
+is a unit test, or a helper inside a unit test, or lives in a file whose top
+object name ends with `-tests`, its name should describe the behavior it
+verifies instead of repeating the word 'test'.
+
+Incorrect:
+
+```eo
+# Tests for foo.
+[] > foo-tests
+  # Test.
+  [] +> can-test-add
+    42 > @
+```
+
+Correct:
+
+```eo
+# Tests for foo.
+[] > foo-tests
+  # Test.
+  [] +> can-add-two-and-two
+    42 > @
+```
diff --git a/src/test/resources/org/eolang/lints/packs/single/test-word/allows-clean-test-names.yaml b/src/test/resources/org/eolang/lints/packs/single/test-word/allows-clean-test-names.yaml
new file mode 100644
index 000000000..7a590f285
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/test-word/allows-clean-test-names.yaml
@@ -0,0 +1,12 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2026 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/tests/test-word.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+input: |
+  [] > foo-tests
+
+    [] +> can-add
+      42 > @
diff --git a/src/test/resources/org/eolang/lints/packs/single/test-word/allows-test-word-in-regular-object.yaml b/src/test/resources/org/eolang/lints/packs/single/test-word/allows-test-word-in-regular-object.yaml
new file mode 100644
index 000000000..2c01ab4b3
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/test-word/allows-test-word-in-regular-object.yaml
@@ -0,0 +1,11 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2026 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/tests/test-word.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+input: |
+  [] > app
+    testing-helper > testing-helper
+    42 > @
diff --git a/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-in-nested-object.yaml b/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-in-nested-object.yaml
new file mode 100644
index 000000000..edaa31153
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-in-nested-object.yaml
@@ -0,0 +1,14 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2026 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/tests/test-word.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=1]
+  - /defects/defect[@line='4']
+input: |
+  [] > foo-tests
+
+    [] +> can-setup
+      tests-helper > tests-helper
+      42 > @
diff --git a/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-in-test-object.yaml b/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-in-test-object.yaml
new file mode 100644
index 000000000..47cdea37d
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-in-test-object.yaml
@@ -0,0 +1,13 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2026 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/tests/test-word.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=1]
+  - /defects/defect[@line='3']
+input: |
+  [] > foo-tests
+
+    [] +> can-test-add
+      42 > @
diff --git a/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-word-in-helper.yaml b/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-word-in-helper.yaml
new file mode 100644
index 000000000..8676d8f90
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/test-word/catches-test-word-in-helper.yaml
@@ -0,0 +1,14 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2026 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/tests/test-word.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=1]
+  - /defects/defect[@line='4']
+input: |
+  [] > foo-tests
+
+    [] > can-run
+      tests-helper > tests-helper
+      42 > @