diff --git a/main.rb b/main.rb
index c9db91e..70b37a8 100644
--- a/main.rb
+++ b/main.rb
@@ -16,10 +16,18 @@ def initialize(filename, version_regex)
     end
 
     def read_versions()
-        File.open(@filename, "r") do |f|
-            f.each_line do |line|
-                @code_tags += line.scan(@version_regex)
+        begin
+            File.open(@filename, "r") do |f|
+                f.each_line do |line|
+                    @code_tags += line.scan(@version_regex)
+                end
             end
+        rescue Errno::ENOENT => e
+            $stderr.puts "Error: #{e}"
+            exit -1
+        rescue TypeError => e
+            $stderr.puts "Error: #{e} (Probably invalid VERSION_REGEX)"
+            exit -1            
         end
     end
 
@@ -39,13 +47,17 @@ def version_updated()
 end
 
 begin
-    regex = ENV["VERSION_REGEX"]  || "/[v]\\d.\\d.\\d/"
+    regex = ENV["VERSION_REGEX"] || ""
     filename = ENV["FILENAME"] || ""
 
     if filename.empty?
         raise "No filename passed as env."
     end
 
+    if regex.empty?
+        regex = "/[v]\\d.\\d.\\d/"
+    end
+
     project = Project.new(filename, eval(regex))
     if not project.version_updated
         raise "Version in code not updated."