diff --git a/CHANGELOG.md b/CHANGELOG.md
index 74afb6a6..b34ee93a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Deprecated
 
+- Deprecate `::atRuleArgs()` (#1191)
 - Support for PHP < 7.2 is deprecated; version 9.0 will require PHP 7.2 or later
   (#1264)
 - Passing a `string` or `null` to `RuleSet::removeRule()` is deprecated
diff --git a/src/CSSList/AtRuleBlockList.php b/src/CSSList/AtRuleBlockList.php
index a424adbe..762d4900 100644
--- a/src/CSSList/AtRuleBlockList.php
+++ b/src/CSSList/AtRuleBlockList.php
@@ -42,6 +42,8 @@ public function atRuleName()
 
     /**
      * @return string
+     *
+     * @deprecated since V8.9.0, will be removed in version 9.0.0. Use the specific getter instead.
      */
     public function atRuleArgs()
     {
diff --git a/src/CSSList/KeyFrame.php b/src/CSSList/KeyFrame.php
index 618308a7..a8706e19 100644
--- a/src/CSSList/KeyFrame.php
+++ b/src/CSSList/KeyFrame.php
@@ -101,6 +101,8 @@ public function atRuleName()
 
     /**
      * @return string|null
+     *
+     * @deprecated since V8.9.0, will be removed in version 9.0.0. Use the specific getter instead.
      */
     public function atRuleArgs()
     {
diff --git a/src/Property/AtRule.php b/src/Property/AtRule.php
index d946a904..cfad3fef 100644
--- a/src/Property/AtRule.php
+++ b/src/Property/AtRule.php
@@ -33,6 +33,8 @@ public function atRuleName();
 
     /**
      * @return string|null
+     *
+     * @deprecated since V8.9.0, will be removed in version 9.0.0. Use the specific getter(s) instead.
      */
     public function atRuleArgs();
 }
diff --git a/src/Property/CSSNamespace.php b/src/Property/CSSNamespace.php
index 188d3581..4e792ee8 100644
--- a/src/Property/CSSNamespace.php
+++ b/src/Property/CSSNamespace.php
@@ -116,6 +116,8 @@ public function atRuleName()
 
     /**
      * @return array<int, string>
+     *
+     * @deprecated since V8.9.0, will be removed in version 9.0.0. Use the specific getters instead.
      */
     public function atRuleArgs()
     {
diff --git a/src/Property/Charset.php b/src/Property/Charset.php
index 1ebff3f3..7bb793a6 100644
--- a/src/Property/Charset.php
+++ b/src/Property/Charset.php
@@ -99,6 +99,8 @@ public function atRuleName()
 
     /**
      * @return string
+     *
+     * @deprecated since V8.9.0, will be removed in version 9.0.0. Use the specific getter instead.
      */
     public function atRuleArgs()
     {
diff --git a/src/Property/Import.php b/src/Property/Import.php
index 5b474493..066f9d9b 100644
--- a/src/Property/Import.php
+++ b/src/Property/Import.php
@@ -94,6 +94,8 @@ public function atRuleName()
 
     /**
      * @return array<int, URL|string>
+     *
+     * @deprecated since V8.9.0, will be removed in version 9.0.0. Use the specific getters instead.
      */
     public function atRuleArgs()
     {
diff --git a/src/RuleSet/AtRuleSet.php b/src/RuleSet/AtRuleSet.php
index e687cb96..834a14d8 100644
--- a/src/RuleSet/AtRuleSet.php
+++ b/src/RuleSet/AtRuleSet.php
@@ -45,6 +45,8 @@ public function atRuleName()
 
     /**
      * @return string
+     *
+     * @deprecated since V8.9.0, will be removed in version 9.0.0. Use the specific getter instead.
      */
     public function atRuleArgs()
     {