diff --git a/drivers/mock/driver.go b/drivers/mock/driver.go
index 68bfb0335..4282453ea 100644
--- a/drivers/mock/driver.go
+++ b/drivers/mock/driver.go
@@ -152,16 +152,19 @@ type TaskConfig struct {
 	StartErrRecoverable bool `codec:"start_error_recoverable"`
 
 	// StartBlockFor specifies a duration in which to block before returning
-	StartBlockFor string `codec:"start_block_for"`
+	StartBlockFor         string `codec:"start_block_for"`
+	startBlockForDuration time.Duration
 
 	// KillAfter is the duration after which the mock driver indicates the task
 	// has exited after getting the initial SIGINT signal
-	KillAfter string `codec:"kill_after"`
+	KillAfter         string `codec:"kill_after"`
+	killAfterDuration time.Duration
 
 	// RunFor is the duration for which the fake task runs for. After this
 	// period the MockDriver responds to the task running indicating that the
 	// task has terminated
-	RunFor string `codec:"run_for"`
+	RunFor         string `codec:"run_for"`
+	runForDuration time.Duration
 
 	// ExitCode is the exit code with which the MockDriver indicates the task
 	// has exited
@@ -195,7 +198,8 @@ type TaskConfig struct {
 	StdoutRepeat int `codec:"stdout_repeat"`
 
 	// StdoutRepeatDur is the duration between repeated outputs.
-	StdoutRepeatDur string `codec:"stdout_repeat_duration"`
+	StdoutRepeatDur      string `codec:"stdout_repeat_duration"`
+	stdoutRepeatDuration time.Duration
 }
 
 type MockTaskState struct {
@@ -298,8 +302,21 @@ func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *cstru
 		return nil, nil, err
 	}
 
-	if driverConfig.StartBlockFor != "" {
-		time.Sleep(parseDuration(driverConfig.StartBlockFor))
+	var err error
+	if driverConfig.startBlockForDuration, err = parseDuration(driverConfig.StartBlockFor); err != nil {
+		return nil, nil, fmt.Errorf("start_block_for %v not a valid duration: %v", driverConfig.StartBlockFor, err)
+	}
+
+	if driverConfig.runForDuration, err = parseDuration(driverConfig.RunFor); err != nil {
+		return nil, nil, fmt.Errorf("run_for %v not a valid duration: %v", driverConfig.RunFor, err)
+	}
+
+	if driverConfig.stdoutRepeatDuration, err = parseDuration(driverConfig.StdoutRepeatDur); err != nil {
+		return nil, nil, fmt.Errorf("stdout_repeat_duration %v not a valid duration: %v", driverConfig.stdoutRepeatDuration, err)
+	}
+
+	if driverConfig.startBlockForDuration != 0 {
+		time.Sleep(driverConfig.startBlockForDuration)
 	}
 
 	if driverConfig.StartErr != "" {
@@ -327,13 +344,13 @@ func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *cstru
 
 	h := &taskHandle{
 		taskConfig:      cfg,
-		runFor:          parseDuration(driverConfig.RunFor),
-		killAfter:       parseDuration(driverConfig.KillAfter),
+		runFor:          driverConfig.runForDuration,
+		killAfter:       driverConfig.killAfterDuration,
 		exitCode:        driverConfig.ExitCode,
 		exitSignal:      driverConfig.ExitSignal,
 		stdoutString:    driverConfig.StdoutString,
 		stdoutRepeat:    driverConfig.StdoutRepeat,
-		stdoutRepeatDur: parseDuration(driverConfig.StdoutRepeatDur),
+		stdoutRepeatDur: driverConfig.stdoutRepeatDuration,
 		logger:          d.logger.With("task_name", cfg.Name),
 		waitCh:          make(chan struct{}),
 		killCh:          killCtx.Done(),
@@ -455,21 +472,3 @@ func (d *Driver) ExecTask(taskID string, cmd []string, timeout time.Duration) (*
 	}
 	return &res, nil
 }
-
-func parseDuration(s string) time.Duration {
-	if s == "" {
-		return time.Duration(0)
-	}
-
-	// check if it's an int64
-	if v, err := strconv.ParseInt(s, 10, 64); err == nil {
-		return time.Duration(v)
-	}
-
-	// try to parse it as duration
-	if v, err := time.ParseDuration(s); err == nil {
-		return v
-	}
-
-	panic(fmt.Errorf("value is not a duration: %v", s))
-}
diff --git a/drivers/mock/utils.go b/drivers/mock/utils.go
new file mode 100644
index 000000000..99ea2dbd4
--- /dev/null
+++ b/drivers/mock/utils.go
@@ -0,0 +1,16 @@
+package mock
+
+import (
+	"time"
+)
+
+// parseDuration parses a duration string, like time.ParseDuration
+// but is empty string friendly, returns a zero time duration
+func parseDuration(s string) (time.Duration, error) {
+	if s == "" {
+		return time.Duration(0), nil
+	}
+
+	// try to parse it as duration
+	return time.ParseDuration(s)
+}
diff --git a/drivers/mock/utils_test.go b/drivers/mock/utils_test.go
new file mode 100644
index 000000000..42458c978
--- /dev/null
+++ b/drivers/mock/utils_test.go
@@ -0,0 +1,29 @@
+package mock
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseDuration(t *testing.T) {
+	t.Run("valid case", func(t *testing.T) {
+		v, err := parseDuration("10m")
+		require.NoError(t, err)
+		require.Equal(t, 10*time.Minute, v)
+	})
+
+	t.Run("invalid case", func(t *testing.T) {
+		v, err := parseDuration("10")
+		require.Error(t, err)
+		require.Equal(t, time.Duration(0), v)
+	})
+
+	t.Run("empty case", func(t *testing.T) {
+		v, err := parseDuration("")
+		require.NoError(t, err)
+		require.Equal(t, time.Duration(0), v)
+	})
+
+}