diff --git a/pkg/captcha/captcha.go b/pkg/captcha/captcha.go
index 17ddc61..8193e0c 100644
--- a/pkg/captcha/captcha.go
+++ b/pkg/captcha/captcha.go
@@ -20,7 +20,8 @@ func NewIntAnswer() Answer {
 
 // Captcha interface that should be implemented by a CAPTCHA.
 type Captcha interface {
-	// Image generates and returns a pointer to an image of CAPTCHA.
+	// Image generates an image of a CAPTCHA according to a passed style
+	// and returns a pointer to it.
 	Image(style string) *image.Image
 	// Answer returns a pregenerated answer.
 	Answer() Answer
@@ -37,14 +38,14 @@ type Captcha interface {
 // All derivatives that embed this struct only need to implement
 // an Image() method.
 type BaseCaptcha struct {
-	answer   Answer
-	solved   bool
-	expireIn time.Time
+	answer Answer
+	solved bool
+	expiry time.Time
 }
 
 func NewBaseCaptcha(expiry time.Duration) *BaseCaptcha {
 	return &BaseCaptcha{
-		expireIn: ExpiryDate(expiry),
+		expiry: ExpiryDate(expiry),
 	}
 }
 
@@ -52,8 +53,6 @@ func (c *BaseCaptcha) Image(style string) *image.Image {
 	return nil
 }
 
-// Answer generates an integer answer for a CAPTCHA or just returns
-// an existing one.
 func (c *BaseCaptcha) Answer() Answer {
 	if c.answer == "" {
 		c.answer = NewIntAnswer()
@@ -61,8 +60,6 @@ func (c *BaseCaptcha) Answer() Answer {
 	return c.answer
 }
 
-// Solve sets solved field to true if given answer is right and returns a result
-// of a check.
 func (c *BaseCaptcha) Solve(answer Answer) bool {
 	c.solved = c.answer == answer
 	return c.solved
@@ -73,7 +70,7 @@ func (c *BaseCaptcha) IsSolved() bool {
 }
 
 func (c *BaseCaptcha) Expiry() time.Time {
-	return c.expireIn
+	return c.expiry
 }
 
 // ExpiryDate returns a date when CAPTCHA expires. It adds a passed