diff --git a/lib/redmine/platform.rb b/lib/redmine/platform.rb
index 4696fa76c..aa92d8e13 100644
--- a/lib/redmine/platform.rb
+++ b/lib/redmine/platform.rb
@@ -25,6 +25,10 @@ module Redmine
            (RUBY_PLATFORM == 'java' && /windows/i.match?(ENV['OS'] || ENV['os']))
       end
 
+      def mswin64?
+        mswin? && RUBY_PLATFORM.include?('x86_64')
+      end
+
       def osx?
         (/(:?darwin)/.match?(RUBY_PLATFORM))
       end
diff --git a/lib/redmine/thumbnail.rb b/lib/redmine/thumbnail.rb
index 4bee4085a..b146a2529 100644
--- a/lib/redmine/thumbnail.rb
+++ b/lib/redmine/thumbnail.rb
@@ -24,7 +24,12 @@ module Redmine
     extend Redmine::Utils::Shell
 
     CONVERT_BIN = (Redmine::Configuration['imagemagick_convert_command'] || 'convert').freeze
-    GS_BIN = (Redmine::Configuration['gs_command'] || 'gs').freeze
+    GS_BIN = (
+      Redmine::Configuration['gs_command'] ||
+      ('gswin64c' if Redmine::Platform.mswin64?) ||
+      ('gwwin32c' if Redmine::Platform.mswin?) ||
+      'gs'
+    ).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 +78,11 @@ 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