diff --git a/hardware/Rakefile b/hardware/Rakefile
index 4f014a1..79744e7 100644
--- a/hardware/Rakefile
+++ b/hardware/Rakefile
@@ -48,10 +48,10 @@ CLOBBER.include(release) if File.exist? release
 desc "set version in schematic and layout"
 task :version => targets.collect{|target| [target[:vsch],target[:vpcb]]}.flatten
 targets.each do |target|
-  CLEAN.include(target[:vsch])
-  CLEAN.include(target[:vpcb])
-  CLOBBER.include("#{target[:name]}_*.sch")
-  CLOBBER.include("#{target[:name]}_*.pcb")
+  CLEAN.include(target[:vsch]) if File.exist? target[:vsch]
+  CLEAN.include(target[:vpcb]) if File.exist? target[:vpcb]
+  CLOBBER.include("#{target[:name]}_*.sch") if File.exist? "#{target[:name]}_*.sch"
+  CLOBBER.include("#{target[:name]}_*.pcb")) if File.exist? "#{target[:name]}_*.pcb"
 end
 =begin
 desc "print schematic and layout (as pdf)"