diff --git a/ChangeLog b/ChangeLog
index 6f2264bfe7..eb1357e880 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -41,9 +41,6 @@ Sat Dec 20 02:18:31 2003  Yukihiro Matsumoto  <matz@ruby-lang.org>
 	* misc/ruby-mode.el (ruby-calculate-indent): proper indentation
 	  inside of parentheses.  [ruby-dev:22308]
 
-	* hash.c (delete_if_i): do not use ST_DELETE for thread safety.
-	  [ruby-dev:21899]  (not fully solved)
-
 Fri Dec 19 21:24:22 2003  GOTOU Yuuzou  <gotoyuzo@notwork.org>
 
 	* lib/webrick/httprequest.rb (HTTPRequest#meta_vars): should not set
diff --git a/dln.c b/dln.c
index 5f7982051e..1dd80c2fe6 100644
--- a/dln.c
+++ b/dln.c
@@ -91,7 +91,7 @@ char *getenv();
 
 int eaccess();
 
-+#if defined(HAVE_DLOPEN) && !defined(USE_DLN_A_OUT) && !defined(_AIX) && !defined(__APPLE__) && !defined(_UNICOSMP)
+#if defined(HAVE_DLOPEN) && !defined(USE_DLN_A_OUT) && !defined(_AIX) && !defined(__APPLE__) && !defined(_UNICOSMP)
 /* dynamic load with dlopen() */
 # define USE_DLN_DLOPEN
 #endif
diff --git a/gc.c b/gc.c
index 8d337cd57a..9e4ac5ae38 100644
--- a/gc.c
+++ b/gc.c
@@ -236,6 +236,8 @@ rb_gc_unregister_address(addr)
     }
 }
 
+#undef GC_DEBUG
+
 void
 rb_global_variable(var)
     VALUE *var;
@@ -266,6 +268,10 @@ typedef struct RVALUE {
 	struct RVarmap varmap; 
 	struct SCOPE   scope;
     } as;
+#ifdef GC_DEBUG
+    char *file;
+    int   line;
+#endif
 } RVALUE;
 
 static RVALUE *freelist = 0;
@@ -346,6 +352,10 @@ rb_newobj()
     obj = (VALUE)freelist;
     freelist = freelist->as.free.next;
     MEMZERO((void*)obj, RVALUE, 1);
+#ifdef GC_DEBUG
+    RANY(obj)->file = ruby_sourcefile;
+    RANY(obj)->line = ruby_sourceline;
+#endif
     return obj;
 }
 
diff --git a/hash.c b/hash.c
index 48c0aba7ac..102682c0b3 100644
--- a/hash.c
+++ b/hash.c
@@ -460,12 +460,12 @@ rb_hash_shift(hash)
 }
 
 static enum st_retval
-delete_if_i(key, value, keys)
-    VALUE key, value, keys;
+delete_if_i(key, value)
+    VALUE key, value;
 {
-    if (key != Qundef && RTEST(rb_yield_values(2, key, value))) {
-	rb_ary_push(keys, key);
-    }
+    if (key == Qundef) return ST_CONTINUE;
+    if (RTEST(rb_yield_values(2, key, value)))
+	return ST_DELETE;
     return ST_CONTINUE;
 }
 
@@ -473,14 +473,8 @@ VALUE
 rb_hash_delete_if(hash)
     VALUE hash;
 {
-    VALUE keys = rb_ary_new();
-    long i;
-
     rb_hash_modify(hash);
-    rb_hash_foreach(hash, delete_if_i, keys);
-    for (i=0; i<RARRAY(keys)->len; i++) {
-	st_delete(RHASH(hash)->tbl, &RARRAY(keys)->ptr[i], 0);
-    }
+    rb_hash_foreach(hash, delete_if_i, 0);
     return hash;
 }