diff --git a/claims.go b/claims.go
index 4430c84..4ea64a7 100644
--- a/claims.go
+++ b/claims.go
@@ -7,9 +7,9 @@ package jwt
 // https://datatracker.ietf.org/doc/html/rfc7519#section-4.1 namely `exp`,
 // `iat`, `nbf`, `iss` and `aud`.
 type Claims interface {
-	GetExpirationTime() *NumericDate
-	GetIssuedAt() *NumericDate
-	GetNotBefore() *NumericDate
-	GetIssuer() string
-	GetAudience() ClaimStrings
+	GetExpirationTime() (*NumericDate, error)
+	GetIssuedAt() (*NumericDate, error)
+	GetNotBefore() (*NumericDate, error)
+	GetIssuer() (string, error)
+	GetAudience() (ClaimStrings, error)
 }
diff --git a/map_claims.go b/map_claims.go
index 93d36ba..9e1857f 100644
--- a/map_claims.go
+++ b/map_claims.go
@@ -2,65 +2,68 @@ package jwt
 
 import (
 	"encoding/json"
+	"errors"
 )
 
 // MapClaims is a claims type that uses the map[string]interface{} for JSON decoding.
 // This is the default claims type if you don't supply one
 type MapClaims map[string]interface{}
 
+var ErrInvalidType = errors.New("invalid type for claim")
+
 // GetExpirationTime implements the Claims interface.
-func (m MapClaims) GetExpirationTime() *NumericDate {
+func (m MapClaims) GetExpirationTime() (*NumericDate, error) {
 	return m.ParseNumericDate("exp")
 }
 
 // GetNotBefore implements the Claims interface.
-func (m MapClaims) GetNotBefore() *NumericDate {
+func (m MapClaims) GetNotBefore() (*NumericDate, error) {
 	return m.ParseNumericDate("nbf")
 }
 
 // GetIssuedAt implements the Claims interface.
-func (m MapClaims) GetIssuedAt() *NumericDate {
+func (m MapClaims) GetIssuedAt() (*NumericDate, error) {
 	return m.ParseNumericDate("iat")
 }
 
 // GetAudience implements the Claims interface.
-func (m MapClaims) GetAudience() ClaimStrings {
+func (m MapClaims) GetAudience() (ClaimStrings, error) {
 	return m.ParseClaimsString("aud")
 }
 
 // GetIssuer implements the Claims interface.
-func (m MapClaims) GetIssuer() string {
+func (m MapClaims) GetIssuer() (string, error) {
 	return m.ParseString("iss")
 }
 
 // ParseNumericDate tries to parse a key in the map claims type as a number
 // date. This will succeed, if the underlying type is either a [float64] or a
 // [json.Number]. Otherwise, nil will be returned.
-func (m MapClaims) ParseNumericDate(key string) *NumericDate {
+func (m MapClaims) ParseNumericDate(key string) (*NumericDate, error) {
 	v, ok := m[key]
 	if !ok {
-		return nil
+		return nil, nil
 	}
 
 	switch exp := v.(type) {
 	case float64:
 		if exp == 0 {
-			return nil
+			return nil, nil
 		}
 
-		return newNumericDateFromSeconds(exp)
+		return newNumericDateFromSeconds(exp), nil
 	case json.Number:
 		v, _ := exp.Float64()
 
-		return newNumericDateFromSeconds(v)
+		return newNumericDateFromSeconds(v), nil
 	}
 
-	return nil
+	return nil, ErrInvalidType
 }
 
 // ParseClaimsString tries to parse a key in the map claims type as a
 // [ClaimsStrings] type, which can either be a string or an array of string.
-func (m MapClaims) ParseClaimsString(key string) ClaimStrings {
+func (m MapClaims) ParseClaimsString(key string) (ClaimStrings, error) {
 	var cs []string
 	switch v := m[key].(type) {
 	case string:
@@ -71,19 +74,33 @@ func (m MapClaims) ParseClaimsString(key string) ClaimStrings {
 		for _, a := range v {
 			vs, ok := a.(string)
 			if !ok {
-				return nil
+				return nil, ErrInvalidType
 			}
 			cs = append(cs, vs)
 		}
 	}
 
-	return cs
+	return cs, nil
 }
 
-// ParseString tries to parse a key in the map claims type as a
-// [string] type. Otherwise, an empty string is returned.
-func (m MapClaims) ParseString(key string) string {
-	iss, _ := m[key].(string)
+// ParseString tries to parse a key in the map claims type as a [string] type.
+// If the key does not exist, an empty string is returned. If the key has the
+// wrong type, an error is returned.
+func (m MapClaims) ParseString(key string) (string, error) {
+	var (
+		ok  bool
+		raw interface{}
+		iss string
+	)
+	raw, ok = m[key]
+	if !ok {
+		return "", nil
+	}
 
-	return iss
+	iss, ok = raw.(string)
+	if !ok {
+		return "", ErrInvalidType
+	}
+
+	return iss, nil
 }
diff --git a/map_claims_test.go b/map_claims_test.go
index fb1d362..0aba922 100644
--- a/map_claims_test.go
+++ b/map_claims_test.go
@@ -1,7 +1,10 @@
 package jwt
 
-/*
-TODO(oxisto): Re-enable tests with validation API
+import (
+	"testing"
+	"time"
+)
+
 func TestVerifyAud(t *testing.T) {
 	var nilInterface interface{}
 	var nilListInterface []interface{}
@@ -39,7 +42,7 @@ func TestVerifyAud(t *testing.T) {
 		{Name: "[]String Aud without match not required", MapClaims: MapClaims{"aud": []string{"not.example.com", "example.example.com"}}, Expected: false, Required: true, Comparison: "example.com"},
 
 		// Required = false
-		{Name: "Empty []String Aud without match required", MapClaims: MapClaims{"aud": []string{""}}, Expected: false, Required: true, Comparison: "example.com"},
+		{Name: "Empty []String Aud without match required", MapClaims: MapClaims{"aud": []string{""}}, Expected: true, Required: false, Comparison: "example.com"},
 
 		// []interface{}
 		{Name: "Empty []interface{} Aud without match required", MapClaims: MapClaims{"aud": nilListInterface}, Expected: true, Required: false, Comparison: "example.com"},
@@ -53,10 +56,17 @@ func TestVerifyAud(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.Name, func(t *testing.T) {
-			got := test.MapClaims.VerifyAudience(test.Comparison, test.Required)
+			var opts []ValidatorOption
 
-			if got != test.Expected {
-				t.Errorf("Expected %v, got %v", test.Expected, got)
+			if test.Required {
+				opts = append(opts, WithAudience(test.Comparison))
+			}
+
+			validator := NewValidator(opts...)
+			got := validator.Validate(test.MapClaims)
+
+			if (got == nil) != test.Expected {
+				t.Errorf("Expected %v, got %v", test.Expected, (got == nil))
 			}
 		})
 	}
@@ -67,9 +77,9 @@ func TestMapclaimsVerifyIssuedAtInvalidTypeString(t *testing.T) {
 		"iat": "foo",
 	}
 	want := false
-	got := mapClaims.VerifyIssuedAt(0, false)
-	if want != got {
-		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, got)
+	got := NewValidator(WithIssuedAt()).Validate(mapClaims)
+	if want != (got == nil) {
+		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, (got == nil))
 	}
 }
 
@@ -78,9 +88,9 @@ func TestMapclaimsVerifyNotBeforeInvalidTypeString(t *testing.T) {
 		"nbf": "foo",
 	}
 	want := false
-	got := mapClaims.VerifyNotBefore(0, false)
-	if want != got {
-		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, got)
+	got := NewValidator().Validate(mapClaims)
+	if want != (got == nil) {
+		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, (got == nil))
 	}
 }
 
@@ -89,33 +99,38 @@ func TestMapclaimsVerifyExpiresAtInvalidTypeString(t *testing.T) {
 		"exp": "foo",
 	}
 	want := false
-	got := mapClaims.VerifyExpiresAt(0, false)
+	got := NewValidator().Validate(mapClaims)
 
-	if want != got {
-		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, got)
+	if want != (got == nil) {
+		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, (got == nil))
 	}
 }
 
 func TestMapClaimsVerifyExpiresAtExpire(t *testing.T) {
-	exp := time.Now().Unix()
+	exp := time.Now()
 	mapClaims := MapClaims{
-		"exp": float64(exp),
+		"exp": float64(exp.Unix()),
 	}
 	want := false
-	got := mapClaims.VerifyExpiresAt(exp, true)
-	if want != got {
-		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, got)
+	got := NewValidator(WithTimeFunc(func() time.Time {
+		return exp
+	})).Validate(mapClaims)
+	if want != (got == nil) {
+		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, (got == nil))
 	}
 
-	got = mapClaims.VerifyExpiresAt(exp+1, true)
-	if want != got {
-		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, got)
+	got = NewValidator(WithTimeFunc(func() time.Time {
+		return exp.Add(1 * time.Second)
+	})).Validate(mapClaims)
+	if want != (got == nil) {
+		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, (got == nil))
 	}
 
 	want = true
-	got = mapClaims.VerifyExpiresAt(exp-1, true)
-	if want != got {
-		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, got)
+	got = NewValidator(WithTimeFunc(func() time.Time {
+		return exp.Add(-1 * time.Second)
+	})).Validate(mapClaims)
+	if want != (got == nil) {
+		t.Fatalf("Failed to verify claims, wanted: %v got %v", want, (got == nil))
 	}
 }
-*/
diff --git a/registered_claims.go b/registered_claims.go
index 0023790..ccdd46a 100644
--- a/registered_claims.go
+++ b/registered_claims.go
@@ -33,26 +33,26 @@ type RegisteredClaims struct {
 }
 
 // GetExpirationTime implements the Claims interface.
-func (c RegisteredClaims) GetExpirationTime() *NumericDate {
-	return c.ExpiresAt
+func (c RegisteredClaims) GetExpirationTime() (*NumericDate, error) {
+	return c.ExpiresAt, nil
 }
 
 // GetNotBefore implements the Claims interface.
-func (c RegisteredClaims) GetNotBefore() *NumericDate {
-	return c.NotBefore
+func (c RegisteredClaims) GetNotBefore() (*NumericDate, error) {
+	return c.NotBefore, nil
 }
 
 // GetIssuedAt implements the Claims interface.
-func (c RegisteredClaims) GetIssuedAt() *NumericDate {
-	return c.IssuedAt
+func (c RegisteredClaims) GetIssuedAt() (*NumericDate, error) {
+	return c.IssuedAt, nil
 }
 
 // GetAudience implements the Claims interface.
-func (c RegisteredClaims) GetAudience() ClaimStrings {
-	return c.Audience
+func (c RegisteredClaims) GetAudience() (ClaimStrings, error) {
+	return c.Audience, nil
 }
 
 // GetIssuer implements the Claims interface.
-func (c RegisteredClaims) GetIssuer() string {
-	return c.Issuer
+func (c RegisteredClaims) GetIssuer() (string, error) {
+	return c.Issuer, nil
 }
diff --git a/validator.go b/validator.go
index 2e41133..3fc37ab 100644
--- a/validator.go
+++ b/validator.go
@@ -2,7 +2,6 @@ package jwt
 
 import (
 	"crypto/subtle"
-	"fmt"
 	"time"
 )
 
@@ -62,9 +61,7 @@ func (v *Validator) Validate(claims Claims) error {
 	}
 
 	if !v.VerifyExpiresAt(claims, now, false) {
-		exp := claims.GetExpirationTime()
-		delta := now.Sub(exp.Time)
-		vErr.Inner = fmt.Errorf("%s by %s", ErrTokenExpired, delta)
+		vErr.Inner = ErrTokenExpired
 		vErr.Errors |= ValidationErrorExpired
 	}
 
@@ -79,9 +76,10 @@ func (v *Validator) Validate(claims Claims) error {
 		vErr.Errors |= ValidationErrorNotValidYet
 	}
 
-	if v.expectedAud != "" && !v.VerifyAudience(claims, v.expectedAud, false) {
-		vErr.Inner = ErrTokenNotValidYet
-		vErr.Errors |= ValidationErrorNotValidYet
+	// If we have an expected audience, we also require the audience claim
+	if v.expectedAud != "" && !v.VerifyAudience(claims, v.expectedAud, true) {
+		vErr.Inner = ErrTokenInvalidAudience
+		vErr.Errors |= ValidationErrorAudience
 	}
 
 	// Finally, we want to give the claim itself some possibility to do some
@@ -104,46 +102,68 @@ func (v *Validator) Validate(claims Claims) error {
 // VerifyAudience compares the aud claim against cmp.
 // If required is false, this method will return true if the value matches or is unset
 func (v *Validator) VerifyAudience(claims Claims, cmp string, req bool) bool {
-	return verifyAud(claims.GetAudience(), cmp, req)
+	aud, err := claims.GetAudience()
+	if err != nil {
+		return false
+	}
+
+	return verifyAud(aud, cmp, req)
 }
 
 // VerifyExpiresAt compares the exp claim against cmp (cmp < exp).
 // If req is false, it will return true, if exp is unset.
 func (v *Validator) VerifyExpiresAt(claims Claims, cmp time.Time, req bool) bool {
-	exp := claims.GetExpirationTime()
-	if exp == nil {
-		return verifyExp(nil, cmp, req, v.leeway)
+	var time *time.Time = nil
+
+	exp, err := claims.GetExpirationTime()
+	if err != nil {
+		return false
+	} else if exp != nil {
+		time = &exp.Time
 	}
 
-	return verifyExp(&exp.Time, cmp, req, v.leeway)
+	return verifyExp(time, cmp, req, v.leeway)
 }
 
 // VerifyIssuedAt compares the iat claim against cmp (cmp >= iat).
 // If req is false, it will return true, if iat is unset.
 func (v *Validator) VerifyIssuedAt(claims Claims, cmp time.Time, req bool) bool {
-	iat := claims.GetIssuedAt()
-	if iat == nil {
-		return verifyIat(nil, cmp, req, v.leeway)
+	var time *time.Time = nil
+
+	iat, err := claims.GetIssuedAt()
+	if err != nil {
+		return false
+	} else if iat != nil {
+		time = &iat.Time
 	}
 
-	return verifyIat(&iat.Time, cmp, req, v.leeway)
+	return verifyIat(time, cmp, req, v.leeway)
 }
 
 // VerifyNotBefore compares the nbf claim against cmp (cmp >= nbf).
 // If req is false, it will return true, if nbf is unset.
 func (v *Validator) VerifyNotBefore(claims Claims, cmp time.Time, req bool) bool {
-	nbf := claims.GetNotBefore()
-	if nbf == nil {
-		return verifyNbf(nil, cmp, req, v.leeway)
+	var time *time.Time = nil
+
+	nbf, err := claims.GetNotBefore()
+	if err != nil {
+		return false
+	} else if nbf != nil {
+		time = &nbf.Time
 	}
 
-	return verifyNbf(&nbf.Time, cmp, req, v.leeway)
+	return verifyNbf(time, cmp, req, v.leeway)
 }
 
 // VerifyIssuer compares the iss claim against cmp.
 // If required is false, this method will return true if the value matches or is unset
 func (v *Validator) VerifyIssuer(claims Claims, cmp string, req bool) bool {
-	return verifyIss(claims.GetIssuer(), cmp, req)
+	iss, err := claims.GetIssuer()
+	if err != nil {
+		return false
+	}
+
+	return verifyIss(iss, cmp, req)
 }
 
 // ----- helpers