diff --git a/barretenberg/cpp/src/barretenberg/transcript/transcript.hpp b/barretenberg/cpp/src/barretenberg/transcript/transcript.hpp
index 43cfc758497b..432ae6fdf6ff 100644
--- a/barretenberg/cpp/src/barretenberg/transcript/transcript.hpp
+++ b/barretenberg/cpp/src/barretenberg/transcript/transcript.hpp
@@ -295,6 +295,7 @@ template <typename Codec_, typename HashFunction_> class BaseTranscript {
     template <typename ChallengeType>
     std::vector<ChallengeType> get_dyadic_powers_of_challenge(const std::string& label, size_t num_challenges)
     {
+        BB_ASSERT(num_challenges > 0, "get_dyadic_powers_of_challenge called with num_challenges=0");
         ChallengeType challenge = get_challenge<ChallengeType>(label);
         std::vector<ChallengeType> pows(num_challenges);
         pows[0] = challenge;
diff --git a/barretenberg/cpp/src/barretenberg/ultra_honk/ultra_verifier.cpp b/barretenberg/cpp/src/barretenberg/ultra_honk/ultra_verifier.cpp
index ed9f7a549153..1b63386f9b23 100644
--- a/barretenberg/cpp/src/barretenberg/ultra_honk/ultra_verifier.cpp
+++ b/barretenberg/cpp/src/barretenberg/ultra_honk/ultra_verifier.cpp
@@ -30,7 +30,10 @@ template <typename Flavor, class IO> size_t UltraVerifier_<Flavor, IO>::compute_
         return static_cast<size_t>(Flavor::VIRTUAL_LOG_N);
     } else {
         // Non-padded: use actual circuit size from VK (native only)
-        return static_cast<size_t>(verifier_instance->get_vk()->log_circuit_size);
+        const size_t log_circuit_size = static_cast<size_t>(verifier_instance->get_vk()->log_circuit_size);
+        BB_ASSERT_GTE(
+            log_circuit_size, static_cast<size_t>(1), "VK log_circuit_size is 0, which is invalid for any circuit");
+        return log_circuit_size;
     }
 }