diff --git a/tool/rbinstall.rb b/tool/rbinstall.rb
index bce02f8624..c40da1a4f3 100755
--- a/tool/rbinstall.rb
+++ b/tool/rbinstall.rb
@@ -854,7 +854,7 @@ module RbInstall
     end
 
     def build_extensions
-    end if /mswin|mingw/ =~ RUBY_PLATFORM
+    end if /mswin|mingw/ =~ RUBY_PLATFORM || RbConfig::CONFIG["CROSS_COMPILING"] == "yes"
 
     def shebang(bin_file_name)
       path = File.join(gem_dir, spec.bindir, bin_file_name)