diff --git a/deps/config/types.go b/deps/config/types.go
index 7f5f2c979..56bf981cb 100644
--- a/deps/config/types.go
+++ b/deps/config/types.go
@@ -342,6 +342,11 @@ type CurioProvingConfig struct {
 // for decoding and encoding from/to TOML
 type Duration time.Duration
 
+func (dur Duration) MarshalText() ([]byte, error) {
+	d := time.Duration(dur)
+	return []byte(d.String()), nil
+}
+
 // UnmarshalText implements interface for TOML decoding
 func (dur *Duration) UnmarshalText(text []byte) error {
 	d, err := time.ParseDuration(string(text))
diff --git a/lib/fastparamfetch/paramfetch.go b/lib/fastparamfetch/paramfetch.go
index 3a86d83dc..46e7290a3 100644
--- a/lib/fastparamfetch/paramfetch.go
+++ b/lib/fastparamfetch/paramfetch.go
@@ -307,7 +307,7 @@ func fetchWithAria2c(ctx context.Context, out, url string) error {
 		return xerrors.New("aria2c not found in PATH")
 	}
 
-	cmd := exec.CommandContext(ctx, aria2cPath, "--continue", "-x16", "-s16", "-dir", filepath.Dir(out), "-o", filepath.Base(out), url)
+	cmd := exec.CommandContext(ctx, aria2cPath, "--continue", "-x16", "-s16", "--dir", filepath.Dir(out), "-o", filepath.Base(out), url)
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr