diff --git a/ChangeLog b/ChangeLog
index 543c1f1a27..faeb6398eb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jan 14 16:53:14 2015  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
+
+	* ext/tk/lib/tkextlib/tcllib/plotchart.rb: fix to invoke correct function
+	  of tcllib. Patch by @zalt50 [fix GH-787]
+
 Wed Jan 14 16:48:15 2015  Tanaka Akira  <akr@fsij.org>
 
 	* lib/resolv.rb (Resolv::DNS::Name#==): Compare an array of Label:Str
diff --git a/ext/tk/lib/tkextlib/tcllib/plotchart.rb b/ext/tk/lib/tkextlib/tcllib/plotchart.rb
index 2f3d79d427..cd52a0ed4b 100644
--- a/ext/tk/lib/tkextlib/tcllib/plotchart.rb
+++ b/ext/tk/lib/tkextlib/tcllib/plotchart.rb
@@ -142,7 +142,7 @@ module Tk::Tcllib::Plotchart
   end
 
   def self.pixel_to_coords(w, x, y)
-    list(tk_call_without_enc('::Plotchart::coordsToPixel', w.path, x, y))
+    list(tk_call_without_enc('::Plotchart::pixelToCoords', w.path, x, y))
   end
 
   def self.determine_scale(*args) # (xmin, xmax, inverted=false)
@@ -311,7 +311,7 @@ module Tk::Tcllib::Plotchart
     end
 
     def pixel_to_coords(x, y)
-      list(tk_call_without_enc('::Plotchart::coordsToPixel', @path, x, y))
+      list(tk_call_without_enc('::Plotchart::pixelToCoords', @path, x, y))
     end
 
     def determine_scale(xmax, ymax)
diff --git a/version.h b/version.h
index 0257ef39bc..f596e9c185 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.0.0"
 #define RUBY_RELEASE_DATE "2015-01-14"
-#define RUBY_PATCHLEVEL 613
+#define RUBY_PATCHLEVEL 614
 
 #define RUBY_RELEASE_YEAR 2015
 #define RUBY_RELEASE_MONTH 1