diff --git a/keystore2/src/crypto/certificate_utils.cpp b/keystore2/src/crypto/certificate_utils.cpp
index 500600f..4b0dca4 100644
--- a/keystore2/src/crypto/certificate_utils.cpp
+++ b/keystore2/src/crypto/certificate_utils.cpp
@@ -544,6 +544,9 @@
 
     bssl::UniquePtr<uint8_t> free_cert_buf(cert_buf);
     auto signature = sign(cert_buf, buf_len);
+    if (signature.empty()) {
+        return CertUtilsError::SignatureFailed;
+    }
 
     if (!ASN1_STRING_set(certificate->signature, signature.data(), signature.size())) {
         return CertUtilsError::BoringSsl;
diff --git a/keystore2/src/crypto/include/certificate_utils.h b/keystore2/src/crypto/include/certificate_utils.h
index 9d41eb8..1e80d80 100644
--- a/keystore2/src/crypto/include/certificate_utils.h
+++ b/keystore2/src/crypto/include/certificate_utils.h
@@ -52,6 +52,7 @@
         MemoryAllocation,
         InvalidArgument,
         UnexpectedNullPointer,
+        SignatureFailed,
     };
 
   private: