diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/SimpleTypeInferer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/SimpleTypeInferer.php
index ab144621edb..6d94391ffd2 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/SimpleTypeInferer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/SimpleTypeInferer.php
@@ -338,14 +338,15 @@ public static function infer(
                 }
 
                 if ($existing_class_constants === null
-                    && $file_source instanceof StatementsAnalyzer
+                    || $existing_class_constants === []
+                    && $file_source !== null
                 ) {
                     try {
                         $foreign_class_constant = $codebase->classlikes->getClassConstantType(
                             $const_fq_class_name,
                             $stmt->name->name,
                             ReflectionProperty::IS_PRIVATE,
-                            $file_source,
+                            $file_source instanceof StatementsAnalyzer ? $file_source : null,
                         );
 
                         if ($foreign_class_constant) {
diff --git a/tests/EnumTest.php b/tests/EnumTest.php
index 77df3b8d659..12322c66698 100644
--- a/tests/EnumTest.php
+++ b/tests/EnumTest.php
@@ -610,6 +610,26 @@ function f(Transport $e): void {
                 'ignored_issues' => [],
                 'php_version' => '8.1',
             ],
+            'backedEnumCaseValueFromClassConstant' => [
+                'code' => <<<'PHP'
+                    <?php
+                    class FooBar {
+                        public const FOO = 'foo';
+                        public const BAR = 2;
+                    }
+
+                    enum FooEnum: string {
+                        case FOO = FooBar::FOO;
+                    }
+
+                    enum BarEnum: int {
+                        case BAR = FooBar::BAR;
+                    }
+                    PHP,
+                'assertions' => [],
+                'ignored_issues' => [],
+                'php_version' => '8.1',
+            ],
         ];
     }
 
@@ -1030,6 +1050,36 @@ function f(string $state): void {}
                 'ignored_issues' => [],
                 'php_version' => '8.1',
             ],
+            'stringBackedEnumCaseValueFromClassConstant' => [
+                'code' => '<?php
+                    class Foo {
+                        const FOO = 1;
+                    }
+
+                    enum Bar: string
+                    {
+                        case Foo = Foo::FOO;
+                    }
+                ',
+                'error_message' => 'InvalidEnumCaseValue',
+                'ignored_issues' => [],
+                'php_version' => '8.1',
+            ],
+            'intBackedEnumCaseValueFromClassConstant' => [
+                'code' => '<?php
+                    class Foo {
+                        const FOO = "foo";
+                    }
+
+                    enum Bar: int
+                    {
+                        case Foo = Foo::FOO;
+                    }
+                ',
+                'error_message' => 'InvalidEnumCaseValue',
+                'ignored_issues' => [],
+                'php_version' => '8.1',
+            ],
         ];
     }
 }