diff --git a/src/pkg/changelog/changelog.go b/src/pkg/changelog/changelog.go
index 3193619..de5b49f 100644
--- a/src/pkg/changelog/changelog.go
+++ b/src/pkg/changelog/changelog.go
@@ -189,7 +189,7 @@
 
 // mappedManifest retrieves a Manifest file from GoB and unmarshals XML.
 // Returns a mapping of repository ID to repository data.
-func mappedManifest(client gitilesProto.GitilesClient, repo string, buildNum string) (map[string]*repo, utils.ChangelogError) {
+func mappedManifest(client gitilesProto.GitilesClient, repo string, buildInput, buildNum string) (map[string]*repo, utils.ChangelogError) {
 	log.Debugf("Retrieving manifest file for build %s\n", buildNum)
 	response, err := utils.DownloadManifest(client, repo, buildNum)
 	if err != nil {
@@ -198,7 +198,7 @@
 		if httpCode == "403" {
 			return nil, utils.ForbiddenError
 		} else if httpCode == "404" {
-			return nil, utils.BuildNotFound(buildNum)
+			return nil, utils.BuildNotFound(buildInput)
 		}
 		return nil, utils.InternalServerError
 	}
@@ -207,7 +207,7 @@
 		log.Errorf("mappedManifest: error retrieving mapped manifest file from repo %s for build %s:\n%v", repo, buildNum, err)
 		httpCode := utils.GitilesErrCode(err)
 		if httpCode == "404" {
-			return nil, utils.BuildNotFound(buildNum)
+			return nil, utils.BuildNotFound(buildInput)
 		}
 		return nil, utils.InternalServerError
 	}
@@ -338,10 +338,10 @@
 	if err != nil {
 		return nil, nil, err
 	}
-	sourceRepos, sourceErr := mappedManifest(manifestClient, repo, sourceBuildNum)
-	targetRepos, targetErr := mappedManifest(manifestClient, repo, targetBuildNum)
+	sourceRepos, sourceErr := mappedManifest(manifestClient, repo, source, sourceBuildNum)
+	targetRepos, targetErr := mappedManifest(manifestClient, repo, target, targetBuildNum)
 	if sourceErr != nil && sourceErr.HTTPCode() == "404" && targetErr != nil && targetErr.HTTPCode() == "404" {
-		return nil, nil, utils.BothBuildsNotFound(croslandURL, source, target)
+		return nil, nil, utils.BothBuildsNotFound(croslandURL, source, target, sourceBuildNum, targetBuildNum)
 	} else if sourceErr != nil {
 		return nil, nil, sourceErr
 	} else if targetErr != nil {
diff --git a/src/pkg/utils/changelogerror.go b/src/pkg/utils/changelogerror.go
index f59a206..b7e734d 100644
--- a/src/pkg/utils/changelogerror.go
+++ b/src/pkg/utils/changelogerror.go
@@ -125,7 +125,7 @@
 }
 
 // BothBuildsNotFound indicates that neither build was not found
-func BothBuildsNotFound(croslandURL, source, target string) *UtilChangelogError {
+func BothBuildsNotFound(croslandURL, source, target, sourceBuildNum, targetBuildNum string) *UtilChangelogError {
 	return &UtilChangelogError{
 		httpCode: "404",
 		header:   "Build Not Found",
@@ -146,8 +146,8 @@
 			"could not be found.",
 			"It may be possible that the inputs are either invalid or both belong to pre-Cusky builds.",
 			"If both of the inputs belong to pre-Cusky builds, please check",
-			croslandLink(croslandURL, source, target),
-			croslandLink(croslandURL, source, target),
+			croslandLink(croslandURL, sourceBuildNum, targetBuildNum),
+			croslandLink(croslandURL, sourceBuildNum, targetBuildNum),
 			"Otherwise, please input valid build numbers",
 			"(example: 13310.1035.0) or valid image names (example: cos-rc-85-13310-1034-0).",
 		),
diff --git a/src/pkg/utils/changelogerror_test.go b/src/pkg/utils/changelogerror_test.go
index f24ea1a..3e68abf 100644
--- a/src/pkg/utils/changelogerror_test.go
+++ b/src/pkg/utils/changelogerror_test.go
@@ -89,8 +89,8 @@
 }
 
 func TestBothBuildsNotFound(t *testing.T) {
-	source := "1a"
-	target := "ddddddd"
+	source := "cos-stable-81-12871-103-0"
+	target := "cos-stable-81-12871-117-0"
 	croslandURL := "https://www.google.com"
 	expectedCode := "404"
 	expectedErrHeader := "Build Not Found"
@@ -116,7 +116,7 @@
 		"Otherwise, please input valid build numbers",
 		"(example: 13310.1035.0) or valid image names (example: cos-rc-85-13310-1034-0).",
 	)
-	err := BothBuildsNotFound(croslandURL, source, target)
+	err := BothBuildsNotFound(croslandURL, source, target, source, target)
 	if err.HTTPCode() != expectedCode {
 		t.Errorf("expected HTTP code %s, got %s", expectedCode, err.HTTPCode())
 	} else if err.Header() != expectedErrHeader {
@@ -131,7 +131,7 @@
 }
 
 func TestBuildNotFound(t *testing.T) {
-	buildNumber := "15000.0.0"
+	buildNumber := "cos-stable-81-12871-117-0"
 	expectedCode := "404"
 	expectedErrHeader := "Build Not Found"
 	expectedErrStr := strings.Join([]string{