diff --git a/src/cosign/cosign.ts b/src/cosign/cosign.ts
index 0e4e430..f280caf 100644
--- a/src/cosign/cosign.ts
+++ b/src/cosign/cosign.ts
@@ -142,15 +142,12 @@ export class Cosign {
         bundlePayload = obj as SerializedBundle;
       }
 
-      if (bundlePayload && signatureManifestDigest) {
+      if (bundlePayload && (signatureManifestDigest || signatureManifestFallbackDigest)) {
+        errors = undefined; // clear errors if we have both payload and manifest digest
         break;
       }
     }
 
-    if (!errors && !bundlePayload) {
-      throw new Error(`Cannot find signature bundle from cosign command output: ${logs}`);
-    }
-
     return {
       bundle: bundlePayload,
       signatureManifestDigest: signatureManifestDigest || signatureManifestFallbackDigest,
diff --git a/src/sigstore/sigstore.ts b/src/sigstore/sigstore.ts
index 6c57afe..8c2b3e5 100644
--- a/src/sigstore/sigstore.ts
+++ b/src/sigstore/sigstore.ts
@@ -106,7 +106,8 @@ export class Sigstore {
                 const errorMessages = signResult.errors.map(e => `- [${e.code}] ${e.message} : ${e.detail}`).join('\n');
                 throw new Error(`Cosign sign command failed with errors:\n${errorMessages}`);
               } else {
-                throw new Error(`Cosign sign command failed with exit code ${execRes.exitCode}`);
+                // prettier-ignore
+                throw new Error(`Cosign sign command failed with: ${execRes.stderr.trim().split(/\r?\n/).filter(line => line.length > 0).pop() ?? 'unknown error'}`);
               }
             }
             const parsedBundle = Sigstore.parseBundle(bundleFromJSON(signResult.bundle));
@@ -209,7 +210,8 @@ export class Sigstore {
             throw lastError;
           }
         } else {
-          throw new Error(`Cosign verify command failed: ${execRes.stderr}`);
+          // prettier-ignore
+          throw new Error(`Cosign verify command failed with: ${execRes.stderr.trim().split(/\r?\n/).filter(line => line.length > 0).pop() ?? 'unknown error'}`);
         }
       }
     }