diff --git a/specs/const/const-declaration.php b/specs/const/const-declaration.php
index 08736856..aebf26d6 100644
--- a/specs/const/const-declaration.php
+++ b/specs/const/const-declaration.php
@@ -471,4 +471,50 @@ function isAnotherNewToken(int $token) : bool
         
         PHP,
     ],
+
+    'Define check of a global class constant' => <<<'PHP'
+    <?php
+    
+    if (!defined('Bar::TEST')) {
+    }
+    if (!defined('\Bar::TEST')) {
+    }
+    if (!defined('\\Bar::TEST')) {
+    }
+    ----
+    <?php
+    
+    namespace Humbug;
+    
+    if (!\defined('Humbug\\Bar::TEST')) {
+    }
+    if (!\defined('Humbug\\Bar::TEST')) {
+    }
+    if (!\defined('Humbug\\Bar::TEST')) {
+    }
+    
+    PHP,
+
+    'Define check of a namespaced class constant' => <<<'PHP'
+    <?php
+    
+    if (!defined('Acme\Bar::TEST')) {
+    }
+    if (!defined('\Acme\Bar::TEST')) {
+    }
+    if (!defined('\\Acme\\Bar::TEST')) {
+    }
+    ----
+    <?php
+    
+    namespace Humbug;
+    
+    if (!\defined('Humbug\\Acme\\Bar::TEST')) {
+    }
+    if (!\defined('Humbug\\Acme\\Bar::TEST')) {
+    }
+    if (!\defined('Humbug\\Acme\\Bar::TEST')) {
+    }
+    
+    PHP,
 ];
diff --git a/src/PhpParser/NodeVisitor/StringScalarPrefixer.php b/src/PhpParser/NodeVisitor/StringScalarPrefixer.php
index 0823c299..9f0c66a0 100644
--- a/src/PhpParser/NodeVisitor/StringScalarPrefixer.php
+++ b/src/PhpParser/NodeVisitor/StringScalarPrefixer.php
@@ -98,6 +98,18 @@ final class StringScalarPrefixer extends NodeVisitorAbstract
         $/ux
         REGEX;
 
+    private const CONSTANT_FETCH_PATTERN = <<<'REGEX'
+        /^
+            (\\)?               # leading backslash
+            (
+                [\p{L}_\d]+     # class-like name
+                \\              # separator
+            )*
+            [\p{L}_\d]+         # class-like name
+            ::[\p{L}_\d]+       # constant-like name
+        $/ux
+        REGEX;
+
     public function __construct(
         private readonly string $prefix,
         private readonly EnrichedReflector $enrichedReflector,
@@ -114,7 +126,10 @@ public function enterNode(Node $node): Node
     private function prefixStringScalar(String_ $string): String_
     {
         if (!(ParentNodeAppender::hasParent($string) && is_string($string->value))
-            || 1 !== native_preg_match(self::CLASS_LIKE_PATTERN, $string->value)
+            || (
+                1 !== native_preg_match(self::CLASS_LIKE_PATTERN, $string->value)
+                && 1 !== native_preg_match(self::CONSTANT_FETCH_PATTERN, $string->value)
+            )
         ) {
             return $string;
         }