diff --git a/cli_args.go b/cli_args.go
index 5ff1861..fa9e35c 100644
--- a/cli_args.go
+++ b/cli_args.go
@@ -114,9 +114,15 @@ func prefixOArgs(osArgs []string) ([]string, error) {
 func convertToDoubleDash(osArgs []string) (out []string) {
 	out = append(out, osArgs...)
 	for i, v := range out {
+		// Leave "-h" alone so the help text keeps working
 		if v == "-h" {
 			continue
 		}
+		// Don't touch anything after "--"
+		if v == "--" {
+			break
+		}
+		// Convert "-foo" to "--foo"
 		if len(v) >= 2 && v[0] == '-' && v[1] != '-' {
 			out[i] = "-" + out[i]
 		}
@@ -125,11 +131,11 @@ func convertToDoubleDash(osArgs []string) (out []string) {
 }
 
 // parseCliOpts - parse command line options (i.e. arguments that start with "-")
-func parseCliOpts() (args argContainer) {
+func parseCliOpts(osArgs []string) (args argContainer) {
 	var err error
 	var opensslAuto string
 
-	osArgsPreprocessed, err := prefixOArgs(os.Args)
+	osArgsPreprocessed, err := prefixOArgs(osArgs)
 	if err != nil {
 		tlog.Fatal.Println(err)
 		os.Exit(exitcodes.Usage)
diff --git a/cli_args_test.go b/cli_args_test.go
index 6dff1f1..97f9473 100644
--- a/cli_args_test.go
+++ b/cli_args_test.go
@@ -3,6 +3,8 @@ package main
 import (
 	"reflect"
 	"testing"
+
+	"github.com/rfjakob/gocryptfs/internal/stupidgcm"
 )
 
 // TestPrefixOArgs checks that the "-o x,y,z" parsing works correctly.
@@ -75,3 +77,105 @@ func TestPrefixOArgs(t *testing.T) {
 		}
 	}
 }
+
+func TestConvertToDoubleDash(t *testing.T) {
+	testcases := []struct {
+		// i is the input
+		i []string
+		// o is the expected output
+		o []string
+	}{
+		{
+			i: nil,
+			o: nil,
+		},
+		{
+			i: []string{"gocryptfs"},
+			o: []string{"gocryptfs"},
+		},
+		{
+			i: []string{"gocryptfs", "foo"},
+			o: []string{"gocryptfs", "foo"},
+		},
+		{
+			i: []string{"gocryptfs", "-v", "-quiet"},
+			o: []string{"gocryptfs", "--v", "--quiet"},
+		},
+		{
+			i: []string{"gocryptfs", "--", "-foo"},
+			o: []string{"gocryptfs", "--", "-foo"},
+		},
+	}
+	for _, tc := range testcases {
+		o := convertToDoubleDash(tc.i)
+		if !reflect.DeepEqual(o, tc.o) {
+			t.Errorf("in=%q\nwant=%q\nhave=%q", tc.i, tc.o, o)
+		}
+	}
+}
+
+func TestParseCliOpts(t *testing.T) {
+	defaultArgs := argContainer{
+		longnames: true,
+		raw64:     true,
+		hkdf:      true,
+		openssl:   stupidgcm.PreferOpenSSL(), // depends on CPU and build flags
+		scryptn:   16,
+	}
+
+	type testcaseContainer struct {
+		// i is the input
+		i []string
+		// o is the expected output
+		o argContainer
+	}
+
+	var testcases []testcaseContainer
+
+	testcases = append(testcases, testcaseContainer{
+		i: []string{"gocryptfs"},
+		o: defaultArgs,
+	})
+
+	o := defaultArgs
+	o.quiet = true
+	testcases = append(testcases, testcaseContainer{
+		i: []string{"gocryptfs", "-q"},
+		o: o,
+	})
+	testcases = append(testcases, testcaseContainer{
+		i: []string{"gocryptfs", "--q"},
+		o: o,
+	})
+	testcases = append(testcases, testcaseContainer{
+		i: []string{"gocryptfs", "-quiet"},
+		o: o,
+	})
+	testcases = append(testcases, testcaseContainer{
+		i: []string{"gocryptfs", "--quiet"},
+		o: o,
+	})
+
+	o = defaultArgs
+	o.exclude = []string{"foo", "bar"}
+	testcases = append(testcases, testcaseContainer{
+		i: []string{"gocryptfs", "-e", "foo", "-e", "bar"},
+		o: o,
+	})
+	testcases = append(testcases, testcaseContainer{
+		i: []string{"gocryptfs", "--exclude", "foo", "--exclude", "bar"},
+		o: o,
+	})
+	/* TODO BROKEN
+	testcases = append(testcases, testcaseContainer{
+		i: []string{"gocryptfs", "--exclude", "foo", "-e", "bar"},
+		o: o,
+	})
+	*/
+	for _, tc := range testcases {
+		o := parseCliOpts(tc.i)
+		if !reflect.DeepEqual(o, tc.o) {
+			t.Errorf("in=%v\nwant=%v\nhave=%v", tc.i, tc.o, o)
+		}
+	}
+}
diff --git a/main.go b/main.go
index 9bd0c78..370feac 100644
--- a/main.go
+++ b/main.go
@@ -166,7 +166,7 @@ func main() {
 	var err error
 	// Parse all command-line options (i.e. arguments starting with "-")
 	// into "args". Path arguments are parsed below.
-	args := parseCliOpts()
+	args := parseCliOpts(os.Args)
 	// Fork a child into the background if "-fg" is not set AND we are mounting
 	// a filesystem. The child will do all the work.
 	if !args.fg && flagSet.NArg() == 2 {