diff --git a/pkg/api/common/helper.go b/pkg/api/common/helper.go
index ef7d9d5a32..4e9580db14 100644
--- a/pkg/api/common/helper.go
+++ b/pkg/api/common/helper.go
@@ -98,6 +98,9 @@ func GetValidPatchVersion(orchType, orchVer string) string {
 
 // RationalizeReleaseAndVersion return a version when it can be rationalized from the input, otherwise ""
 func RationalizeReleaseAndVersion(orchType, orchRel, orchVer string) (version string) {
+	// ignore "v" prefix in orchestrator version and release: "v1.8.0" is equivalent to "1.8.0", "v1.9" is equivalent to "1.9"
+	orchVer = strings.TrimPrefix(orchVer, "v")
+	orchRel = strings.TrimPrefix(orchRel, "v")
 	supportedVersions, defaultVersion := GetSupportedVersions(orchType)
 	if supportedVersions == nil {
 		return ""
diff --git a/pkg/api/common/helper_test.go b/pkg/api/common/helper_test.go
index 15a46fda58..688ca83fda 100644
--- a/pkg/api/common/helper_test.go
+++ b/pkg/api/common/helper_test.go
@@ -80,4 +80,13 @@ func Test_RationalizeReleaseAndVersion(t *testing.T) {
 		t.Errorf("It is not 1.5.8")
 	}
 
+	version = RationalizeReleaseAndVersion(Kubernetes, "", "v1.8.8")
+	if version != KubernetesVersion1Dot8Dot8 {
+		t.Errorf("It is not Kubernetes version %s", KubernetesVersion1Dot8Dot8)
+	}
+
+	version = RationalizeReleaseAndVersion(Kubernetes, "v1.9", "")
+	if version != KubernetesVersion1Dot9Dot3 {
+		t.Errorf("It is not Kubernetes version %s", KubernetesVersion1Dot9Dot3)
+	}
 }
diff --git a/pkg/api/vlabs/validate_test.go b/pkg/api/vlabs/validate_test.go
index d336385c69..f964df9ecb 100644
--- a/pkg/api/vlabs/validate_test.go
+++ b/pkg/api/vlabs/validate_test.go
@@ -63,6 +63,16 @@ func Test_OrchestratorProfile_Validate(t *testing.T) {
 	if err := o.Validate(true); err != nil {
 		t.Errorf("should not have failed on old patch version during update valdiation")
 	}
+
+	o = &OrchestratorProfile{
+		OrchestratorType:    "Kubernetes",
+		OrchestratorVersion: "v1.9.0",
+	}
+
+	if err := o.Validate(false); err != nil {
+		t.Errorf("should not have failed on version with v prefix")
+	}
+
 }
 
 func Test_KubernetesConfig_Validate(t *testing.T) {