diff --git a/ethosu/regor/common/logging.hpp b/ethosu/regor/common/logging.hpp
index aa838c5f0e5bf147fc62081db9d2945fdf13cc97..b5370387906b81afff172ceabb5046688a3b0e8e 100644
--- a/ethosu/regor/common/logging.hpp
+++ b/ethosu/regor/common/logging.hpp
@@ -1,5 +1,6 @@
 //
 // SPDX-FileCopyrightText: Copyright 2021, 2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
+// SPDX-FileCopyrightText: Copyright 2025 Meta Platforms, Inc. and affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -118,7 +119,7 @@ public:
         {
             if ( _mask & _context->_filterMask )
             {
-                _context->Write(fmt::format(format, std::forward<TYPES>(args)...));
+                _context->Write(fmt::format(fmt::runtime(format), std::forward<TYPES>(args)...));
             }
         }
 
@@ -127,7 +128,7 @@ public:
         {
             if ( _mask & _context->_filterMask )
             {
-                _context->Write(fmt::format(format.c_str(), std::forward<TYPES>(args)...));
+                _context->Write(fmt::format(fmt::runtime(format.c_str()), std::forward<TYPES>(args)...));
             }
         }
 
diff --git a/ethosu/regor/tflite/tflite_model_semantics.cpp b/ethosu/regor/tflite/tflite_model_semantics.cpp
index c27b97c714db07977974548c167ad1911bcb52dc..262ab28b69c87e34fb580d82a677a516f01c9755 100644
--- a/ethosu/regor/tflite/tflite_model_semantics.cpp
+++ b/ethosu/regor/tflite/tflite_model_semantics.cpp
@@ -1,5 +1,6 @@
 //
 // SPDX-FileCopyrightText: Copyright 2023-2025 Arm Limited and/or its affiliates <open-source-office@arm.com>
+// SPDX-FileCopyrightText: Copyright 2025 Meta Platforms, Inc. and affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -708,7 +709,7 @@ void ConstraintInput8bit(const Operator &op, const SubGraph &subgraph, const Bui
     if ( !(ifm->type() == TensorType::INT8 || ifm->type() == TensorType::UINT8) )
     {
         std::string constraint = "IFM has to be 8bit";
-        std::string extra = fmt::format("IFM type={}, OFM type={}", EnumNameTensorType(ifm->type()));
+        std::string extra = fmt::format("IFM type={}, ", EnumNameTensorType(ifm->type()));
         throw InvalidTfLiteException(constraint, extra, op, subgraph, builtinOperator);
     }
 }
@@ -732,7 +733,7 @@ void ConstraintArgmaxOutput(const Operator &op, const SubGraph &subgraph, const
     if ( !(ofm->type() == TensorType::INT32 || ofm->type() == TensorType::INT64) )
     {
         std::string constraint = "For IFM that are signed, OFM must also be signed";
-        std::string extra = fmt::format("IFM type={}, OFM type={}", EnumNameTensorType(ofm->type()));
+        std::string extra = fmt::format("OFM type={} ", EnumNameTensorType(ofm->type()));
         throw InvalidTfLiteException(constraint, extra, op, subgraph, builtinOperator);
     }
 }