diff --git a/alpha/veneer/semver/semver.go b/alpha/veneer/semver/semver.go
index 6b1e484f8..be50a7ba7 100644
--- a/alpha/veneer/semver/semver.go
+++ b/alpha/veneer/semver/semver.go
@@ -2,18 +2,20 @@ package semver
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"io"
 	"sort"
 
 	"github.com/blang/semver/v4"
+	"k8s.io/apimachinery/pkg/util/errors"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"sigs.k8s.io/yaml"
+
 	"github.com/operator-framework/operator-registry/alpha/action"
 	"github.com/operator-framework/operator-registry/alpha/declcfg"
 	"github.com/operator-framework/operator-registry/alpha/property"
 	"github.com/operator-framework/operator-registry/pkg/image"
-	"k8s.io/apimachinery/pkg/util/errors"
-	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/apimachinery/pkg/util/yaml"
 )
 
 // data passed into this module externally
@@ -140,7 +142,10 @@ func readFile(reader io.Reader) (*semverVeneer, error) {
 		GenerateMinorChannels: true,
 		AvoidSkipPatch:        false,
 	}
-	if err := yaml.Unmarshal(data, &sv); err != nil {
+	if err := yaml.Unmarshal(data, &sv, func(decoder *json.Decoder) *json.Decoder {
+		decoder.DisallowUnknownFields()
+		return decoder
+	}); err != nil {
 		return nil, err
 	}
 	return &sv, nil
diff --git a/alpha/veneer/semver/semver_test.go b/alpha/veneer/semver/semver_test.go
index 68b2b2988..19d9fd3b3 100644
--- a/alpha/veneer/semver/semver_test.go
+++ b/alpha/veneer/semver/semver_test.go
@@ -1,12 +1,14 @@
 package semver
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/blang/semver/v4"
+	"github.com/stretchr/testify/require"
+
 	"github.com/operator-framework/operator-registry/alpha/declcfg"
 	"github.com/operator-framework/operator-registry/alpha/property"
-	"github.com/stretchr/testify/require"
 )
 
 func TestLinkChannels(t *testing.T) {
@@ -615,3 +617,93 @@ func TestBailOnVersionBuildMetadata(t *testing.T) {
 		require.Error(t, err)
 	})
 }
+
+func TestReadFile(t *testing.T) {
+	type testCase struct {
+		name       string
+		input      string
+		assertions func(*testing.T, *semverVeneer, error)
+	}
+	testCases := []testCase{
+		{
+			name: "valid",
+			input: `---
+schema: olm.semver
+generateMajorChannels: true
+generateMinorChannels: true
+candidate:
+    bundles:
+        - image: quay.io/foo/olm:testoperator.v0.1.0
+        - image: quay.io/foo/olm:testoperator.v0.1.1
+        - image: quay.io/foo/olm:testoperator.v0.1.2
+        - image: quay.io/foo/olm:testoperator.v0.1.3
+        - image: quay.io/foo/olm:testoperator.v0.2.0
+        - image: quay.io/foo/olm:testoperator.v0.2.1
+        - image: quay.io/foo/olm:testoperator.v0.2.2
+        - image: quay.io/foo/olm:testoperator.v0.3.0
+        - image: quay.io/foo/olm:testoperator.v1.0.0
+        - image: quay.io/foo/olm:testoperator.v1.0.1
+        - image: quay.io/foo/olm:testoperator.v1.1.0
+fast:
+    bundles:
+        - image: quay.io/foo/olm:testoperator.v0.2.1
+        - image: quay.io/foo/olm:testoperator.v0.2.2
+        - image: quay.io/foo/olm:testoperator.v0.3.0
+        - image: quay.io/foo/olm:testoperator.v1.0.1
+        - image: quay.io/foo/olm:testoperator.v1.1.0
+stable:
+    bundles:
+        - image: quay.io/foo/olm:testoperator.v1.0.1
+`,
+			assertions: func(t *testing.T, veneer *semverVeneer, err error) {
+				require.NotNil(t, veneer)
+				require.NoError(t, err)
+			},
+		},
+		{
+			name: "unknown channel prefix",
+			input: `---
+schema: olm.semver
+generateMajorChannels: true
+generateMinorChannels: true
+candidate:
+    bundles:
+        - image: quay.io/foo/olm:testoperator.v0.1.0
+        - image: quay.io/foo/olm:testoperator.v0.1.1
+        - image: quay.io/foo/olm:testoperator.v0.1.2
+        - image: quay.io/foo/olm:testoperator.v0.1.3
+        - image: quay.io/foo/olm:testoperator.v0.2.0
+        - image: quay.io/foo/olm:testoperator.v0.2.1
+        - image: quay.io/foo/olm:testoperator.v0.2.2
+        - image: quay.io/foo/olm:testoperator.v0.3.0
+        - image: quay.io/foo/olm:testoperator.v1.0.0
+        - image: quay.io/foo/olm:testoperator.v1.0.1
+        - image: quay.io/foo/olm:testoperator.v1.1.0
+fast:
+    bundles:
+        - image: quay.io/foo/olm:testoperator.v0.2.1
+        - image: quay.io/foo/olm:testoperator.v0.2.2
+        - image: quay.io/foo/olm:testoperator.v0.3.0
+        - image: quay.io/foo/olm:testoperator.v1.0.1
+        - image: quay.io/foo/olm:testoperator.v1.1.0
+stable:
+    bundles:
+        - image: quay.io/foo/olm:testoperator.v1.0.1
+invalid:
+    bundles:
+        - image: quay.io/foo/olm:testoperator.v1.0.1
+`,
+			assertions: func(t *testing.T, veneer *semverVeneer, err error) {
+				require.Nil(t, veneer)
+				require.EqualError(t, err, `error unmarshaling JSON: while decoding JSON: json: unknown field "invalid"`)
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			sv, err := readFile(strings.NewReader(tc.input))
+			tc.assertions(t, sv, err)
+		})
+	}
+}