diff --git a/ChangeLog b/ChangeLog
index 149edad772..894cba10c6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri Sep 13 18:35:12 2002  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
+
+	* eval.c (rb_eval): avoid uninitialized global/class variable
+	  warnings at `||='.  [ruby-dev:18278]
+
+	* parse.y (stmt, arg): ditto
+
 Fri Sep 13 13:28:04 2002  WATANABE Hirofumi  <eban@ruby-lang.org>
 
 	* lib/mkmf.rb ($INSTALLFILES): avoid warning when $VERBOSE mode.
diff --git a/eval.c b/eval.c
index 70cb068858..8d93cbcfd5 100644
--- a/eval.c
+++ b/eval.c
@@ -2891,7 +2891,7 @@ rb_eval(self, n)
 	goto again;
 
       case NODE_OP_ASGN_OR:
-	if ((node->nd_aid && !rb_ivar_defined(self, node->nd_aid)) ||
+	if ((node->nd_aid && !is_defined(self, node->nd_head, 0)) ||
 	    !RTEST(result = rb_eval(self, node->nd_head))) {
 	    node = node->nd_value;
 	    goto again;
diff --git a/parse.y b/parse.y
index 6eedddc6d1..a323b7f011 100644
--- a/parse.y
+++ b/parse.y
@@ -49,6 +49,11 @@
 #define is_const_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_CONST)
 #define is_class_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_CLASS)
 
+#define is_asgn_or_id(id) ((is_notop_id(id)) && \
+	(((id)&ID_SCOPE_MASK) == ID_GLOBAL || \
+	 ((id)&ID_SCOPE_MASK) == ID_INSTANCE || \
+	 ((id)&ID_SCOPE_MASK) == ID_CLASS))
+
 NODE *ruby_eval_tree_begin = 0;
 NODE *ruby_eval_tree = 0;
 
@@ -462,7 +467,7 @@ stmt		: kALIAS fitem {lex_state = EXPR_FNAME;} fitem
 			    if ($2 == tOROP) {
 				$1->nd_value = $3;
 				$$ = NEW_OP_ASGN_OR(gettable(vid), $1);
-				if (is_instance_id(vid)) {
+				if (is_asgn_or_id(vid)) {
 				    $$->nd_aid = vid;
 				}
 			    }
@@ -828,7 +833,7 @@ arg		: lhs '=' arg
 			    if ($2 == tOROP) {
 				$1->nd_value = $3;
 				$$ = NEW_OP_ASGN_OR(gettable(vid), $1);
-				if (is_instance_id(vid)) {
+				if (is_asgn_or_id(vid)) {
 				    $$->nd_aid = vid;
 				}
 			    }