diff --git a/tool/sync_default_gems.rb b/tool/sync_default_gems.rb
index d403a01667..e9ce28a87e 100755
--- a/tool/sync_default_gems.rb
+++ b/tool/sync_default_gems.rb
@@ -21,7 +21,6 @@ module SyncDefaultGems
     English: "ruby/English",
     abbrev: "ruby/abbrev",
     benchmark: "ruby/benchmark",
-    bigdecimal: "ruby/bigdecimal",
     cgi: "ruby/cgi",
     csv: 'ruby/csv',
     date: 'ruby/date',
@@ -339,14 +338,6 @@ module SyncDefaultGems
       cp_r("#{upstream}/test/test_syslog.rb", "test")
       cp_r("#{upstream}/syslog.gemspec", "ext/syslog")
       `git checkout ext/syslog/depend`
-    when "bigdecimal"
-      rm_rf(%w[ext/bigdecimal test/bigdecimal])
-      cp_r("#{upstream}/ext/bigdecimal", "ext")
-      cp_r("#{upstream}/sample", "ext/bigdecimal")
-      cp_r("#{upstream}/lib", "ext/bigdecimal")
-      cp_r("#{upstream}/test/bigdecimal", "test")
-      cp_r("#{upstream}/bigdecimal.gemspec", "ext/bigdecimal")
-      `git checkout ext/bigdecimal/depend`
     when "pathname"
       rm_rf(%w[ext/pathname test/pathname])
       cp_r("#{upstream}/ext/pathname", "ext")