diff --git a/vlib/v/pref/options_test.v b/vlib/v/pref/options_test.v
index e83a510bb2..b552e61f4c 100644
--- a/vlib/v/pref/options_test.v
+++ b/vlib/v/pref/options_test.v
@@ -4,49 +4,53 @@ import time
 
 const vexe = @VEXE
 
-const vroot = os.real_path(@VMODROOT)
-
-fn testsuite_begin() {
-	os.chdir(vroot) or {}
-}
-
 fn test_cflags() ? {
-	println('> test whether -cflags is passed to the backend C compiler')
-	compilation := os.execute('"$vexe" -cflags NONSENSE_OPTION examples/hello_world.v')
-	assert compilation.exit_code != 0
-	println('> NONSENSE_OPTION failed the C build, OK')
-	//
+	os.chdir(os.real_path(@VMODROOT)) or {}
 	mut debug_arg := '-g3 -O0'
 	mut optimised_arg := '-O1'
 	$if msvc {
 		debug_arg = '/MDd /D_DEBUG'
 		optimised_arg = '/O1'
 	}
-	tmpdir := os.temp_dir()
 	//
-	dbgexe := os.join_path(os.temp_dir(), 'debug_hw.exe')
-	debug_sw := time.new_stopwatch()
-	debug_compilation := os.execute('"$vexe" -cflags "$debug_arg" -o "$dbgexe" examples/hello_world.v')
-	debug_delta := debug_sw.elapsed().microseconds()
-	assert debug_compilation.exit_code == 0
-	debug_file_size := os.file_size(dbgexe)
-	assert debug_file_size > 0
-	println('> debug build took: $debug_delta ms with "$debug_arg", file size: $debug_file_size')
+	println('> test whether -cflags is passed to the backend C compiler')
+	fail := custom_compile('failing.exe', 'NONSENSE_OPTION')
+	assert fail.compilation.exit_code != 0
+	println('> NONSENSE_OPTION failed the C build, OK')
 	//
-	optexe := os.join_path(os.temp_dir(), 'optimised_hw.exe')
-	optimised_sw := time.new_stopwatch()
-	optimised_compilation := os.execute('"$vexe" -cflags "$optimised_arg" -o "$optexe" examples/hello_world.v')
-	optimised_delta := optimised_sw.elapsed().microseconds()
-	assert optimised_compilation.exit_code == 0
-	optimised_file_size := os.file_size(optexe)
-	assert optimised_file_size > 0
-	println('> optimised build took: $optimised_delta ms with "$optimised_arg", file size: $optimised_file_size')
+	dbg := custom_compile('debug_hw.exe', debug_arg)
+	assert dbg.compilation.exit_code == 0
+	assert dbg.file_size > 0
+	//
+	opt := custom_compile('optimised_hw.exe', optimised_arg)
+	assert opt.compilation.exit_code == 0
+	assert opt.file_size > 0
 	//
 	$if !tinyc {
 		// tcc does almost no optimisations, so the differences are very insignificant
-		assert optimised_file_size != debug_file_size // optimised_file_size should be smaller in general, but not on the Ubuntu CI for some reason :-|
-		assert optimised_delta >= debug_delta
+		assert opt.file_size != dbg.file_size // optimised_file_size should be smaller in general, but not on the Ubuntu CI for some reason :-|
+		// assert optimised_delta >= debug_delta // this is not reliable on the CIs :-|
 	}
-	os.rm(optexe) or {}
-	os.rm(dbgexe) or {}
+	os.rm(opt.exe) or {}
+	os.rm(dbg.exe) or {}
+}
+
+fn custom_compile(fname string, cflags_options string) Results {
+	mut res := Results{}
+	res.exe = os.join_path(os.temp_dir(), fname)
+	res.sw = time.new_stopwatch()
+	res.compilation = os.execute('"$vexe" -cflags "$cflags_options" -o "$res.exe" examples/hello_world.v')
+	res.delta = res.sw.elapsed().microseconds()
+	res.file_size = os.file_size(res.exe)
+	println('> $fname build took: $res.delta ms with "$cflags_options", file size: $res.file_size')
+	return res
+}
+
+struct Results {
+mut:
+	exe         string
+	sw          time.StopWatch
+	compilation os.Result
+	delta       i64
+	file_size   u64
 }