diff --git a/gc.c b/gc.c
index ad67023321..157dfce495 100644
--- a/gc.c
+++ b/gc.c
@@ -6346,8 +6346,8 @@ wmap_inspect(VALUE self)
 
     TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
     str = rb_sprintf("-<%"PRIsVALUE":%p", c, (void *)self);
-    if (w->obj2wmap) {
-	st_foreach(w->obj2wmap, wmap_inspect_i, str);
+    if (w->wmap2obj) {
+	st_foreach(w->wmap2obj, wmap_inspect_i, str);
     }
     RSTRING_PTR(str)[0] = '#';
     rb_str_cat2(str, ">");
diff --git a/test/ruby/test_weakmap.rb b/test/ruby/test_weakmap.rb
index c0d1747d2a..0f147a6b0f 100644
--- a/test/ruby/test_weakmap.rb
+++ b/test/ruby/test_weakmap.rb
@@ -28,6 +28,14 @@ class TestWeakMap < Test::Unit::TestCase
   alias test_member? test_include?
   alias test_key? test_include?
 
+  def test_inspect
+    x = Object.new
+    k = BasicObject.new
+    @wm[k] = x
+    assert_match(/\A\#<#{@wm.class.name}:[^:]+:\s\#<BasicObject:[^:]*>\s=>\s\#<Object:[^:]*>>\z/,
+                 @wm.inspect)
+  end
+
   def test_each
     m = __callee__[/test_(.*)/, 1]
     x1 = Object.new