diff --git a/cli/limeOEM.cpp b/cli/limeOEM.cpp
index c210ad39..fef9bc3a 100644
--- a/cli/limeOEM.cpp
+++ b/cli/limeOEM.cpp
@@ -151,9 +151,11 @@ int main(int argc, char** argv)
     {
         uint64_t serialNumber = device->GetDescriptor().serialNumber;
         cerr << "Board serial number: " << serialNumber << " (";
+        stringstream ss;
+        ss << std::hex << std::setw(2) << std::setfill('0');
         for (size_t i = 0; i < sizeof(serialNumber); ++i)
-            cerr << hex << "0x" << std::setw(2) << std::setfill('0') << ((serialNumber >> 8 * i) & 0xFF) << " ";
-        cerr << ")" << endl;
+            ss << "0x" << ((serialNumber >> 8 * i) & 0xFF) << " ";
+        cerr << ss.str() << ")" << endl;
 
         PrintOEMTestReporter reporter(serialNumber, reportFilename);
         reporter.ReportColumn("S/N", std::to_string(serialNumber));
diff --git a/src/protocols/LMS64CProtocol.cpp b/src/protocols/LMS64CProtocol.cpp
index 27517dd7..dbfa2b1b 100644
--- a/src/protocols/LMS64CProtocol.cpp
+++ b/src/protocols/LMS64CProtocol.cpp
@@ -876,8 +876,9 @@ OpStatus WriteSerialNumber(ISerialPort& port, const std::vector<uint8_t>& serial
             bytes.resize(currentSerial.size());
             std::stringstream ss;
             ss << "Padding serial number to:";
+            ss << std::hex << std::setw(2) << std::setfill('0');
             for (size_t i = 0; i < bytes.size(); ++i)
-                ss << std::setw(2) << std::setfill('0') << std::hex << bytes[i] << " ";
+                ss << "0x" << static_cast<uint32_t>(bytes[i]) << " ";
             lime::debug(ss.str());
         }
     }
@@ -933,9 +934,9 @@ OpStatus WriteSerialNumber(ISerialPort& port, const std::vector<uint8_t>& serial
         return OpStatus::Error;
 
     std::stringstream ss;
-    ss << "Serial number written:";
+    ss << "Serial number written:" << std::hex << std::setw(2) << std::setfill('0');
     for (uint8_t b : bytes)
-        ss << std::hex << b << " ";
+        ss << "0x" << static_cast<uint32_t>(b) << " ";
     lime::info(ss.str());
     // wait for things to settle, otherwise reading serial immediately will return zeroes
     std::this_thread::sleep_for(std::chrono::milliseconds(100));