diff --git a/src/Psalm/Config.php b/src/Psalm/Config.php
index da10ef51091..ac4355b557c 100644
--- a/src/Psalm/Config.php
+++ b/src/Psalm/Config.php
@@ -1790,11 +1790,22 @@ public function getReportingLevelForMethod(string $issue_type, string $method_id
 
     public function getReportingLevelForFunction(string $issue_type, string $function_id): ?string
     {
+        $level = null;
         if (isset($this->issue_handlers[$issue_type])) {
-            return $this->issue_handlers[$issue_type]->getReportingLevelForFunction($function_id);
+            $level = $this->issue_handlers[$issue_type]->getReportingLevelForFunction($function_id);
+
+            if ($level === null && $issue_type === 'UndefinedFunction') {
+                // undefined functions trigger global namespace fallback
+                // so we should also check reporting levels for the symbol in global scope
+                $root_function_id = preg_replace('/.*\\\/', '', $function_id);
+                if ($root_function_id !== $function_id) {
+                    /** @psalm-suppress PossiblyUndefinedStringArrayOffset https://github.com/vimeo/psalm/issues/7656 */
+                    $level = $this->issue_handlers[$issue_type]->getReportingLevelForFunction($root_function_id);
+                }
+            }
         }
 
-        return null;
+        return $level;
     }
 
     public function getReportingLevelForArgument(string $issue_type, string $function_id): ?string
diff --git a/tests/Config/ConfigTest.php b/tests/Config/ConfigTest.php
index 6a15f41c9ac..867099ff754 100644
--- a/tests/Config/ConfigTest.php
+++ b/tests/Config/ConfigTest.php
@@ -355,6 +355,36 @@ public function testIssueHandler(): void
         $this->assertFalse($config->reportIssueInFile('MissingReturnType', realpath('src/Psalm/Type.php')));
     }
 
+    public function testGlobalUndefinedFunctionSuppression(): void
+    {
+        $this->project_analyzer = $this->getProjectAnalyzerWithConfig(
+            Config::loadFromXML(
+                dirname(__DIR__, 2),
+                '<?xml version="1.0"?>
+                <psalm>
+                    <projectFiles>
+                        <directory name="src" />
+                        <directory name="tests" />
+                    </projectFiles>
+
+                    <issueHandlers>
+                        <UndefinedFunction>
+                            <errorLevel type="suppress">
+                                <referencedFunction name="zzz"/>
+                            </errorLevel>
+                        </UndefinedFunction>
+                    </issueHandlers>
+                </psalm>'
+            )
+        );
+
+        $config = $this->project_analyzer->getConfig();
+        $this->assertSame(
+            Config::REPORT_SUPPRESS,
+            $config->getReportingLevelForFunction('UndefinedFunction', 'Some\Namespace\zzz')
+        );
+    }
+
     public function testMultipleIssueHandlers(): void
     {
         $this->project_analyzer = $this->getProjectAnalyzerWithConfig(