diff --git a/library/rubygems/basic_specification.rb b/library/rubygems/basic_specification.rb
index 470a6ebc8b..2ad6e7a67e 100644
--- a/library/rubygems/basic_specification.rb
+++ b/library/rubygems/basic_specification.rb
@@ -53,8 +53,6 @@ def base_dir
   # Return true if this spec can require +file+.
 
   def contains_requirable_file? file
-    build_extensions
-
     suffixes = Gem.suffixes
 
     full_require_paths.any? do |dir|
diff --git a/library/rubygems/request_set.rb b/library/rubygems/request_set.rb
index fb54e344bd..260077ae14 100644
--- a/library/rubygems/request_set.rb
+++ b/library/rubygems/request_set.rb
@@ -125,8 +125,6 @@ def install options, &block # :yields: request, installer
 
     sorted_requests.each do |req|
       if req.installed? then
-        req.spec.spec.build_extensions
-
         if @always_install.none? { |spec| spec == req.spec.spec } then
           yield req, nil if block_given?
           next
diff --git a/library/rubygems/specification.rb b/library/rubygems/specification.rb
index f4e609a5eb..fc1ccb138a 100644
--- a/library/rubygems/specification.rb
+++ b/library/rubygems/specification.rb
@@ -1414,6 +1414,7 @@ def build_args
   # the gem.build_complete file is missing.
 
   def build_extensions # :nodoc:
+    return
     return if default_gem?
     return if extensions.empty?
     return if installed_by_version < Gem::Version.new('2.2.0.preview.2')
diff --git a/library/rubygems/stub_specification.rb b/library/rubygems/stub_specification.rb
index 221dc1d404..452735c75c 100644
--- a/library/rubygems/stub_specification.rb
+++ b/library/rubygems/stub_specification.rb
@@ -54,6 +54,7 @@ def activated?
   end
 
   def build_extensions # :nodoc:
+    return
     return if default_gem?
     return if extensions.empty?