diff --git a/connector/saml/saml.go b/connector/saml/saml.go
index 7fad1cc3..8b55252a 100644
--- a/connector/saml/saml.go
+++ b/connector/saml/saml.go
@@ -17,6 +17,7 @@ import (
 	"github.com/Sirupsen/logrus"
 	"github.com/beevik/etree"
 	dsig "github.com/russellhaering/goxmldsig"
+	"github.com/russellhaering/goxmldsig/etreeutils"
 
 	"github.com/coreos/dex/connector"
 )
@@ -500,8 +501,9 @@ func verify(validator *dsig.ValidationContext, data []byte) (signed []byte, err
 		verified = true
 		doc.SetRoot(transformedResponse)
 	}
-	assertion := response.SelectElement("Assertion")
-	if assertion == nil {
+	// Ensures xmlns are copied down to the assertion element when they are defined in the root
+	assertion, err := etreeutils.NSSelectOne(response, "urn:oasis:names:tc:SAML:2.0:assertion", "Assertion")
+	if err != nil {
 		return nil, fmt.Errorf("response does not contain an Assertion element")
 	}
 	transformedAssertion, err := validator.Validate(assertion)
diff --git a/connector/saml/saml_test.go b/connector/saml/saml_test.go
index a2bc49b2..cba0fe12 100644
--- a/connector/saml/saml_test.go
+++ b/connector/saml/saml_test.go
@@ -86,6 +86,10 @@ func TestVerify(t *testing.T) {
 	runVerify(t, "testdata/okta-ca.pem", "testdata/okta-resp.xml", true)
 }
 
+func TestVerifyUnsignedMessageAndSignedAssertionWithRootXmlNs(t *testing.T) {
+	runVerify(t, "testdata/oam-ca.pem", "testdata/oam-resp.xml", true)
+}
+
 func TestVerifySignedMessageAndUnsignedAssertion(t *testing.T) {
 	runVerify(t, "testdata/idp-cert.pem", "testdata/idp-resp-signed-message.xml", true)
 }
diff --git a/connector/saml/testdata/oam-ca.pem b/connector/saml/testdata/oam-ca.pem
new file mode 100644
index 00000000..41645dda
--- /dev/null
+++ b/connector/saml/testdata/oam-ca.pem
@@ -0,0 +1,13 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/connector/saml/testdata/oam-resp.xml b/connector/saml/testdata/oam-resp.xml
new file mode 100644
index 00000000..99d14877
--- /dev/null
+++ b/connector/saml/testdata/oam-resp.xml
@@ -0,0 +1 @@
+<samlp:Response xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" xmlns:dsig="http://www.w3.org/2000/09/xmldsig#" xmlns:enc="http://www.w3.org/2001/04/xmlenc#" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" xmlns:x500="urn:oasis:names:tc:SAML:2.0:profiles:attribute:X500" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" Destination="http://127.0.0.1:5556/callback" ID="id-IWlPTptSB-PlR80dwt8ZhVeG70mrz7nPvTVrhduK" InResponseTo="_e66b3a98-831c-4c96-5706-b63fe0549624" IssueInstant="2016-12-12T16:54:35Z" Version="2.0"><saml:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">https://deaoam-dev02.jpl.nasa.gov:14101/oam/fed</saml:Issuer><samlp:Status><samlp:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/></samlp:Status><saml:Assertion ID="id-rT9rTqxdQC9j34YhVeNayUWC9EbIBgym6gp-MZt-" IssueInstant="2016-12-12T16:54:35Z" Version="2.0"><saml:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">https://deaoam-dev02.jpl.nasa.gov:14101/oam/fed</saml:Issuer><dsig:Signature><dsig:SignedInfo><dsig:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><dsig:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/><dsig:Reference URI="#id-rT9rTqxdQC9j34YhVeNayUWC9EbIBgym6gp-MZt-"><dsig:Transforms><dsig:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/><dsig:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/></dsig:Transforms><dsig:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><dsig:DigestValue>z1HD/59hv6UOd5+jeG+ihaFWLgI=</dsig:DigestValue></dsig:Reference></dsig:SignedInfo><dsig:SignatureValue>I99oG5kiOfIgbXYa21z/TOmzftTkFnXe9ObhBNSKit9kAhT93apYROqqXv4Ax96P144Ld7ERX1hgJsytK8LC2874Pk7QrSNm4zvW3x0D4GR4lM06CvJK/EhIur3TrCUJDPigvyP7TJitheCyBejwt0x0lqNP/OzR3tMbAIMRoho=</dsig:SignatureValue></dsig:Signature><saml:Subject><saml:NameID Format="urn:oasis:names:tc:SAML:2.0:nameid-format:persistent" NameQualifier="https://deaoam-dev02.jpl.nasa.gov:14101/oam/fed" SPNameQualifier="JSAuth">pkieu</saml:NameID><saml:SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer"><saml:SubjectConfirmationData InResponseTo="_e66b3a98-831c-4c96-5706-b63fe0549624" NotOnOrAfter="2016-12-12T16:59:35Z" Recipient="http://127.0.0.1:5556/callback"/></saml:SubjectConfirmation></saml:Subject><saml:Conditions NotBefore="2016-12-12T16:54:35Z" NotOnOrAfter="2016-12-12T16:59:35Z"><saml:AudienceRestriction><saml:Audience>JSAuth</saml:Audience></saml:AudienceRestriction></saml:Conditions><saml:AuthnStatement AuthnInstant="2016-12-12T16:54:10Z" SessionIndex="id-l3NCbxKoBfUZcuKhlotMuIF3ydgYJgGGG6BGTTU6" SessionNotOnOrAfter="2016-12-12T17:54:35Z"><saml:AuthnContext><saml:AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport</saml:AuthnContextClassRef></saml:AuthnContext></saml:AuthnStatement></saml:Assertion></samlp:Response>