diff --git a/ChangeLog b/ChangeLog
index c0da5b57ad..2d21be7709 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Mar 14 09:50:03 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* compile.c (insn_data_to_s_detail), iseq.c (insn_operand_intern):
+	  fixed format specifiers.
+
 Sun Mar 14 07:20:17 2010  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* file.c (EXPAND_PATH_BUFFER): make it back to usascii, to prevent
diff --git a/compile.c b/compile.c
index 3a910bea0c..1db4e9c6b8 100644
--- a/compile.c
+++ b/compile.c
@@ -4973,7 +4973,7 @@ insn_data_to_s_detail(INSN *iobj)
 
 	for (j = 0; types[j]; j++) {
 	    char type = types[j];
-	    printf("str: %p, type: %c\n", str, type);
+	    printf("str: %"PRIxVALUE", type: %c\n", str, type);
 
 	    switch (type) {
 	      case TS_OFFSET:	/* label(destination position) */
diff --git a/iseq.c b/iseq.c
index fc13d70cc0..1600cb0f2d 100644
--- a/iseq.c
+++ b/iseq.c
@@ -797,7 +797,7 @@ insn_operand_intern(rb_iseq_t *iseq,
 	break;
 
       case TS_IC:
-	ret = rb_sprintf("<ic:%d>", (struct iseq_inline_cache_entry *)op - iseq->ic_entries);
+	ret = rb_sprintf("<ic:%"PRIdPTRDIFF">", (struct iseq_inline_cache_entry *)op - iseq->ic_entries);
 	break;
 
       case TS_CDHASH: