Index: Zend/zend_compile.c
===================================================================
RCS file: /repository/ZendEngine2/zend_compile.c,v
retrieving revision 1.547
diff -u -r1.547 zend_compile.c
--- Zend/zend_compile.c	25 Feb 2004 17:23:50 -0000	1.547
+++ Zend/zend_compile.c	25 Feb 2004 23:23:42 -0000
@@ -1733,7 +1733,7 @@
 		return 0;
 	}
 
-	for (i=0; i < proto->common.num_args; i++) {
+	for (i = 0; i < proto->common.num_args; i++) {
 		if (ZEND_LOG_XOR(fe->common.arg_info[i].class_name, proto->common.arg_info[i].class_name)) {
 			/* Only one has a type hint and the other one doesn't */
 			return 0;
@@ -1828,8 +1828,11 @@
 		}
 	}
 
-	if (!zend_do_perform_implementation_check(child)) {
-		zend_error(E_COMPILE_ERROR, "Declaration of %s::%s() must be compatible with that of %s::%s()", ZEND_FN_SCOPE_NAME(child), child->common.function_name, ZEND_FN_SCOPE_NAME(child->common.prototype), child->common.prototype->common.function_name);
+	/* Perform implementation check when implementing an interface */
+	if (child->common.prototype->common.scope->ce_flags & ZEND_ACC_INTERFACE) {
+		if (!zend_do_perform_implementation_check(child)) {
+			zend_error(E_COMPILE_ERROR, "Declaration of %s::%s() must be compatible with that of %s::%s()", ZEND_FN_SCOPE_NAME(child), child->common.function_name, ZEND_FN_SCOPE_NAME(child->common.prototype), child->common.prototype->common.function_name);
+		}
 	}
 
 	return 0;