diff --git a/lib/redmine/platform.rb b/lib/redmine/platform.rb
index 4696fa76c..fa735be4b 100644
--- a/lib/redmine/platform.rb
+++ b/lib/redmine/platform.rb
@@ -20,6 +20,10 @@
 module Redmine
   module Platform
     class << self
+      def mswin64?
+        mswin? && RUBY_PLATFORM.include?('x86_64')
+      end
+
       def mswin?
         (/(:?mswin|mingw)/.match?(RUBY_PLATFORM)) ||
            (RUBY_PLATFORM == 'java' && /windows/i.match?(ENV['OS'] || ENV['os']))
diff --git a/lib/redmine/thumbnail.rb b/lib/redmine/thumbnail.rb
index 4bee4085a..5c3e18cc6 100644
--- a/lib/redmine/thumbnail.rb
+++ b/lib/redmine/thumbnail.rb
@@ -24,7 +24,13 @@ module Redmine
     extend Redmine::Utils::Shell
 
     CONVERT_BIN = (Redmine::Configuration['imagemagick_convert_command'] || 'convert').freeze
-    GS_BIN = (Redmine::Configuration['gs_command'] || 'gs').freeze
+    DEFAULT_GS_COMMAND =
+      if Redmine::Platform.mswin?
+        Redmine::Platform.mswin64? ? 'gswin64c' : 'gswin32c'
+      else
+        'gs'
+      end
+    GS_BIN = (Redmine::Configuration['gs_command'] || DEFAULT_GS_COMMAND).freeze
     ALLOWED_TYPES = %w(image/bmp image/gif image/jpeg image/png application/pdf)
 
     # Generates a thumbnail for the source image to target
@@ -73,15 +79,11 @@ module Redmine
     def self.gs_available?
       return @gs_available if defined?(@gs_available)
 
-      if Redmine::Platform.mswin?
+      begin
+        `#{shell_quote GS_BIN} -version`
+        @gs_available = $?.success?
+      rescue
         @gs_available = false
-      else
-        begin
-          `#{shell_quote GS_BIN} -version`
-          @gs_available = $?.success?
-        rescue
-          @gs_available = false
-        end
       end
       logger.warn("gs binary (#{GS_BIN}) not available") unless @gs_available
       @gs_available