diff --git a/php_gnupg.h b/php_gnupg.h
index 7ce6e3f..81383ed 100644
--- a/php_gnupg.h
+++ b/php_gnupg.h
@@ -46,7 +46,7 @@ typedef struct gnupg_object{
     HashTable *decryptkeys;
 } gnupg_object;
 
-zend_class_entry *gnupg_class_entry;
+static zend_class_entry *gnupg_class_entry;
 
 PHP_MINIT_FUNCTION(gnupg);
 PHP_MSHUTDOWN_FUNCTION(gnupg);
diff --git a/php_gnupg_keylistiterator.h b/php_gnupg_keylistiterator.h
index 2ddba0c..6e7e2e7 100644
--- a/php_gnupg_keylistiterator.h
+++ b/php_gnupg_keylistiterator.h
@@ -41,7 +41,7 @@ typedef struct _gnupg_keylistiterator_object{
     zval pattern;
 } gnupg_keylistiterator_object;
 
-zend_class_entry *gnupg_keylistiterator_class_entry;
+static zend_class_entry *gnupg_keylistiterator_class_entry;
 
 PHP_METHOD(gnupg_keylistiterator, __construct);
 PHP_METHOD(gnupg_keylistiterator, current);