diff --git a/pkg/controller/ingress-shim/sync.go b/pkg/controller/ingress-shim/sync.go
index 1a7791290..dc7075b86 100644
--- a/pkg/controller/ingress-shim/sync.go
+++ b/pkg/controller/ingress-shim/sync.go
@@ -3,6 +3,7 @@ package controller
 import (
 	"context"
 	"fmt"
+	"reflect"
 	"strconv"
 
 	"github.com/golang/glog"
@@ -133,6 +134,12 @@ func (c *Controller) buildCertificates(ing *extv1beta1.Ingress) (new, update []*
 			updateCrt.Spec.SecretName = tls.SecretName
 			updateCrt.Spec.IssuerRef.Name = issuerName
 			updateCrt.Spec.IssuerRef.Kind = issuerKind
+			updateCrt.Spec.IssuerRef.Kind = issuerKind
+			updateCrt.Spec.IssuerRef.Kind = issuerKind
+			err = c.setIssuerSpecificConfig(updateCrt, issuer, ing, tls)
+			if err != nil {
+				return nil, nil, err
+			}
 			updateCrts = append(updateCrts, updateCrt)
 		} else {
 			newCrts = append(newCrts, crt)
@@ -169,6 +176,12 @@ func certNeedsUpdate(a, b *v1alpha1.Certificate) bool {
 		return true
 	}
 
+	if a.Spec.ACME != nil && b.Spec.ACME != nil {
+		if !reflect.DeepEqual(a.Spec.ACME.Config, b.Spec.ACME.Config) {
+			return true
+		}
+	}
+
 	return false
 }
 
diff --git a/pkg/controller/ingress-shim/sync_test.go b/pkg/controller/ingress-shim/sync_test.go
index 1524c7460..085081544 100644
--- a/pkg/controller/ingress-shim/sync_test.go
+++ b/pkg/controller/ingress-shim/sync_test.go
@@ -568,6 +568,98 @@ func TestBuildCertificates(t *testing.T) {
 							Name: "issuer-name",
 							Kind: "Issuer",
 						},
+						ACME: &v1alpha1.ACMECertificateConfig{
+							Config: []v1alpha1.ACMECertificateDomainConfig{
+								{
+									Domains: []string{"example.com"},
+									ACMESolverConfig: v1alpha1.ACMESolverConfig{
+										HTTP01: &v1alpha1.ACMECertificateHTTP01Config{
+											Ingress: "",
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			Name: "should update a certificate's config if an incorrect Certificate exists",
+			Ingress: &extv1beta1.Ingress{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "ingress-name",
+					Namespace: "ingress-namespace",
+					Annotations: map[string]string{
+						issuerNameAnnotation:              "issuer-name",
+						acmeIssuerChallengeTypeAnnotation: "http01",
+						ingressClassAnnotation:            "toot-ing",
+					},
+				},
+				Spec: extv1beta1.IngressSpec{
+					TLS: []extv1beta1.IngressTLS{
+						{
+							Hosts:      []string{"example.com"},
+							SecretName: "existing-crt",
+						},
+					},
+				},
+			},
+			IssuerLister: []*v1alpha1.Issuer{buildACMEIssuer("issuer-name", "ingress-namespace")},
+			CertificateLister: []*v1alpha1.Certificate{
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "existing-crt",
+						Namespace: "ingress-namespace",
+					},
+					Spec: v1alpha1.CertificateSpec{
+						DNSNames:   []string{"example.com"},
+						SecretName: "existing-crt",
+						IssuerRef: v1alpha1.ObjectReference{
+							Name: "issuer-name",
+							Kind: "Issuer",
+						},
+						ACME: &v1alpha1.ACMECertificateConfig{
+							Config: []v1alpha1.ACMECertificateDomainConfig{
+								{
+									Domains: []string{"wrong-example.com"},
+									ACMESolverConfig: v1alpha1.ACMESolverConfig{
+										HTTP01: &v1alpha1.ACMECertificateHTTP01Config{
+											Ingress: "wrong-ingress",
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			ExpectedUpdate: []*v1alpha1.Certificate{
+				&v1alpha1.Certificate{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "existing-crt",
+						Namespace: "ingress-namespace",
+					},
+					Spec: v1alpha1.CertificateSpec{
+						DNSNames:   []string{"example.com"},
+						SecretName: "existing-crt",
+						IssuerRef: v1alpha1.ObjectReference{
+							Name: "issuer-name",
+							Kind: "Issuer",
+						},
+						ACME: &v1alpha1.ACMECertificateConfig{
+							Config: []v1alpha1.ACMECertificateDomainConfig{
+								{
+									Domains: []string{"example.com"},
+									ACMESolverConfig: v1alpha1.ACMESolverConfig{
+										HTTP01: &v1alpha1.ACMECertificateHTTP01Config{
+											Ingress:      "",
+											IngressClass: strPtr("toot-ing"),
+										},
+									},
+								},
+							},
+						},
 					},
 				},
 			},