diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 5efc22c104..38bb6aba46 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -328,10 +328,11 @@ class FormulaInstaller
     return unless File.exist? f.lib
 
     valid_libraries = %w(.a .dylib .framework .la .o .so)
+    allowed_non_libraries = %w(.jar .prl)
     non_libraries = f.lib.children.select do |g|
       next if g.directory?
       extname = g.extname
-      (extname != ".jar") and (not valid_libraries.include? extname)
+      (not allowed_non_libraries.include? extname) and (not valid_libraries.include? extname)
     end
 
     unless non_libraries.empty?