diff --git a/tests/test-355chapters.rb b/tests/test-355chapters.rb
old mode 100644
new mode 100755
index 6ab2c3ada..f35ff36e9
--- a/tests/test-355chapters.rb
+++ b/tests/test-355chapters.rb
@@ -14,7 +14,7 @@ end
 # Invalid files:
 invalid.sort.each do |chapters|
   test chapters do
-    messages = merge "#{source} --chapters #{chapters}", :exit_code => 2
+    messages, exit_code = merge("#{source} --chapters #{chapters}", :exit_code => 2)
     messages.detect { |line| /The\s+XML\s+chapter\s+file.*contains\s+an\s+error/i.match line } ? :ok : :bad
   end
 end
diff --git a/tests/test-356tags.rb b/tests/test-356tags.rb
old mode 100644
new mode 100755
index 00f313c45..fa6621593
--- a/tests/test-356tags.rb
+++ b/tests/test-356tags.rb
@@ -14,7 +14,7 @@ end
 # Invalid files:
 invalid.sort.each do |tags|
   test tags do
-    messages = merge "--tags 0:#{tags} #{source}", :exit_code => 2
+    messages, exit_code = merge("--tags 0:#{tags} #{source}", :exit_code => 2)
     messages.detect { |line| /The\s+XML\s+tag\s+file.*contains\s+an\s+error/i.match line } ? :ok : :bad
   end
 end
diff --git a/tests/test-378deprecated_iso_639_2_codes.rb b/tests/test-378deprecated_iso_639_2_codes.rb
old mode 100644
new mode 100755
index 45f77622f..3cecddf51
--- a/tests/test-378deprecated_iso_639_2_codes.rb
+++ b/tests/test-378deprecated_iso_639_2_codes.rb
@@ -5,7 +5,7 @@ the_file = "data/mkv/deprecated-languages.mkv"
 # T_378deprecated_iso_639_2_codes
 describe "mkvmerge / handling deprecated ISO 639-2 language codes"
 test "identification" do
-  identify(the_file).select { |e| /language:/.match(e) }.collect { |e| e.chomp.gsub(/.*language:(\w+).*/, '\1') }.compact.sort.join('+')
+  identify(the_file)[0].select { |e| /language:/.match(e) }.collect { |e| e.chomp.gsub(/.*language:(\w+).*/, '\1') }.compact.sort.join('+')
 end
 
 test_merge the_file
diff --git a/tests/test-390timecode_info_on_resync.rb b/tests/test-390timecode_info_on_resync.rb
old mode 100644
new mode 100755
index d2bca77ce..96d8e5fb0
--- a/tests/test-390timecode_info_on_resync.rb
+++ b/tests/test-390timecode_info_on_resync.rb
@@ -4,6 +4,6 @@
 describe 'mkvmerge / output timecodes on resync'
 
 test 'data/mkv/resync-after-broken.mkv' do
-  output = merge('data/mkv/resync-after-broken.mkv', :args => '--ui-language en_US').join('')
+  output = merge('data/mkv/resync-after-broken.mkv', :args => '--ui-language en_US')[0].join('')
   [/last.*timecode.*before.*error/, /first.*cluster.*timecode.*resync/].collect { |re| re.match(output) ? 'ok' : 'BAD' }.join('+')
 end
diff --git a/tests/test.d/simple_test.rb b/tests/test.d/simple_test.rb
index 754cd7c11..a5e36afe9 100644
--- a/tests/test.d/simple_test.rb
+++ b/tests/test.d/simple_test.rb
@@ -257,9 +257,15 @@ class SimpleTest
     end
 
     puts "COMMAND #{command}" if ENV['DEBUG']
-    self.error "system command failed: #{command} (#{$? >> 8})" if !system(command) && (options[:exit_code] != ($? >> 8))
 
-    return IO.readlines(temp_file.path) if temp_file
+    exit_code = 0
+    if !system(command)
+      exit_code = $? >> 8
+      self.error "system command failed: #{command} (#{exit_code})" if options[:exit_code] != exit_code
+    end
+
+    return IO.readlines(temp_file.path), exit_code if temp_file
+    return exit_code
   end
 
   def error reason