diff --git a/ChangeLog b/ChangeLog
index 49b0d11c3c..547c29252a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Sep  3 20:47:02 2006  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ruby.h (SYMBOL_P): Qnil and Qfalse are not Symbol.
+
 Sun Sep  3 15:32:44 2006  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/mkmf.rb: get rid of nil.to_s.
diff --git a/ruby.h b/ruby.h
index c6cf32186d..df0ae75e9f 100644
--- a/ruby.h
+++ b/ruby.h
@@ -195,7 +195,7 @@ VALUE rb_ull2inum(unsigned LONG_LONG);
 #define IMMEDIATE_MASK 0x03
 #define IMMEDIATE_P(x) ((VALUE)(x) & IMMEDIATE_MASK)
 
-#define SYMBOL_P(x) (!IMMEDIATE_P(x) && RBASIC(x)->klass == rb_cSymbol)
+#define SYMBOL_P(x) (!SPECIAL_CONST_P(x) && RBASIC(x)->klass == rb_cSymbol)
 VALUE rb_id2sym(ID);
 ID rb_sym2id(VALUE);
 #define ID2SYM(x) rb_id2sym(x)