Index: php5-5.3.3.1/Zend/zend_extensions.c
===================================================================
--- php5-5.3.3.1.orig/Zend/zend_extensions.c	2010-01-25 15:47:19.000000000 +0100
+++ php5-5.3.3.1/Zend/zend_extensions.c	2016-02-24 14:54:24.000000000 +0100
@@ -105,6 +105,14 @@
 #endif
 		DL_UNLOAD(handle);
 		return FAILURE;
+        } else if (zend_get_extension(new_extension->name)) {
+                fprintf(stderr, "Cannot load %s - extension already loaded\n", new_extension->name);
+/* See http://support.microsoft.com/kb/190351 */
+#ifdef PHP_WIN32
+                fflush(stderr);
+#endif
+                DL_UNLOAD(handle);
+                return FAILURE;
 	}
 
 	return zend_register_extension(new_extension, handle);