diff --git a/src/Translator.php b/src/Translator.php
index 097d407d..e060d909 100644
--- a/src/Translator.php
+++ b/src/Translator.php
@@ -3535,6 +3535,20 @@ private function genExtensionIncludeHeaderFiles(): string
                     $declarationHeaders[] = $header;
                 }
             }
+            // Nano policy mode (Windows, the WINDOWS_DLL backend) emits a direct
+            // php_main() call inside RINIT instead of relying on ZendVM eval, so
+            // the entry function's declaration header — which carries the
+            // php_main() prototype — must be visible to this translation unit.
+            // True Nano mode keeps php_main() encapsulated inside the separate
+            // nano-entry translation unit, so only the policy path needs this.
+            if ($this->isNanoPolicyMode() && $this->hasFunction(self::ENTRY_FUNCTION)) {
+                $entryHeader = $this->declarationHeaderFiles[
+                    $this->getFunction(self::ENTRY_FUNCTION)->sourceFile
+                ] ?? null;
+                if ($entryHeader !== null && !in_array($entryHeader, $declarationHeaders, true)) {
+                    $declarationHeaders[] = $entryHeader;
+                }
+            }
         }
 
         return $this->renderIncludeHeaderFiles([