diff --git a/ChangeLog b/ChangeLog
index c342abc1e9..237567d8b9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jun 30 21:23:20 2017  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* vsnprintf.c (BSD_vfprintf): sign and hex-prefix should not be counted
+	  in precision. [Bug #8916]
+
 Fri Jun 30 21:20:14 2017  Koichi Sasada  <ko1@atdot.net>
 
 	* thread.c (ruby_thread_stack_overflow): disable VM events when stack
diff --git a/strftime.c b/strftime.c
index 83550e9a7f..e8099a3f12 100644
--- a/strftime.c
+++ b/strftime.c
@@ -497,7 +497,7 @@ rb_strftime_with_timespec(char *s, size_t maxsize, const char *format, rb_encodi
 				goto unknown;
                         }
 			i = snprintf(s, endp - s, (padding == ' ' ? "%+*ld" : "%+.*ld"),
-				     precision + 1, sign * (off / 3600));
+				     precision + (padding == ' '), sign * (off / 3600));
 			if (i < 0) goto err;
 			if (sign < 0 && off < 3600) {
 				*(padding == ' ' ? s + i - 2 : s) = '-';
diff --git a/version.h b/version.h
index f512c73c56..0005fdf3bc 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.3.5"
 #define RUBY_RELEASE_DATE "2017-06-30"
-#define RUBY_PATCHLEVEL 329
+#define RUBY_PATCHLEVEL 330
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 6
diff --git a/vsnprintf.c b/vsnprintf.c
index 075bb4b2fe..0af1f5a573 100644
--- a/vsnprintf.c
+++ b/vsnprintf.c
@@ -1117,11 +1117,11 @@ number:			if ((dprec = prec) >= 0)
 		 */
 		fieldsz = size;
 long_len:
-		if (sign)
-			fieldsz++;
-		if (flags & HEXPREFIX)
-			fieldsz += 2;
 		realsz = dprec > fieldsz ? dprec : fieldsz;
+		if (sign)
+			realsz++;
+		if (flags & HEXPREFIX)
+			realsz += 2;
 
 		/* right-adjusting blank padding */
 		if ((flags & (LADJUST|ZEROPAD)) == 0)
@@ -1143,10 +1143,6 @@ long_len:
 
 		/* leading zeroes from decimal precision */
 		PAD_L(dprec - fieldsz, zeroes);
-		if (sign)
-			fieldsz--;
-		if (flags & HEXPREFIX)
-			fieldsz -= 2;
 
 		/* the string or number proper */
 #ifdef FLOATING_POINT