diff --git a/platform/posix/darwin/cdcacmdarwin.cpp b/platform/posix/darwin/cdcacmdarwin.cpp
index 81a1011..ea322e6 100644
--- a/platform/posix/darwin/cdcacmdarwin.cpp
+++ b/platform/posix/darwin/cdcacmdarwin.cpp
@@ -2,6 +2,7 @@
 #include "icsneo/device/founddevice.h"
 #include <mutex>
 #include <vector>
+#include <cctype>
 #include <CoreFoundation/CoreFoundation.h>
 #include <IOKit/IOKitLib.h>
 #include <IOKit/usb/IOUSBLib.h>
@@ -166,9 +167,11 @@ void CDCACM::Find(std::vector<FoundDevice>& found) {
 		if(CFGetTypeID(serialProp) != CFStringGetTypeID())
 			continue;
 		// We can static cast here because we have verified the type to be a CFString
-		const std::string serial = CFStringToString(static_cast<CFStringRef>(serialProp));
+		std::string serial = CFStringToString(static_cast<CFStringRef>(serialProp));
 		if(serial.empty())
 			continue;
+		for(char& c : serial)
+			c = static_cast<char>(toupper(c));
 		device.serial[serial.copy(device.serial, sizeof(device.serial)-1)] = '\0';
 
 		// Add a factory to make the driver
diff --git a/platform/posix/ftdi.cpp b/platform/posix/ftdi.cpp
index 08d6676..a96328a 100644
--- a/platform/posix/ftdi.cpp
+++ b/platform/posix/ftdi.cpp
@@ -5,6 +5,7 @@
 #include <cstring>
 #include <memory>
 #include <utility>
+#include <cctype>
 #include <algorithm>
 #include <libusb.h>
 
@@ -24,6 +25,8 @@ void FTDI::Find(std::vector<FoundDevice>& found) {
 		FoundDevice d;
 		strncpy(d.serial, serial.c_str(), deviceSerialBufferLength - 1);
 		d.serial[deviceSerialBufferLength - 1] = '\0'; // strncpy does not write a null terminator if serial is too long
+		for(size_t i = 0; i < deviceSerialBufferLength - 1; i++)
+			d.serial[i] = toupper(serial[i]);
 		std::string devHandle = serial;
 		auto it = std::find(handles.begin(), handles.end(), devHandle);
 		size_t foundHandle = SIZE_MAX;
diff --git a/platform/posix/linux/cdcacmlinux.cpp b/platform/posix/linux/cdcacmlinux.cpp
index ea89f35..5f151f1 100644
--- a/platform/posix/linux/cdcacmlinux.cpp
+++ b/platform/posix/linux/cdcacmlinux.cpp
@@ -7,6 +7,7 @@
 #include <fstream>
 #include <map>
 #include <algorithm>
+#include <cctype>
 #include <termios.h>
 #include <fcntl.h>
 #include <unistd.h>
@@ -67,6 +68,8 @@ public:
 		try {
 			std::ifstream reader(ss.str());
 			std::getline(reader, serial);
+			for (auto& c : serial)
+				c = toupper(c);
 		} catch(...) {
 			succeeded = false;
 			return;
diff --git a/platform/windows/vcp.cpp b/platform/windows/vcp.cpp
index 57c1f0b..b5166bf 100644
--- a/platform/windows/vcp.cpp
+++ b/platform/windows/vcp.cpp
@@ -9,6 +9,7 @@
 #include <cwctype>
 #include <algorithm>
 #include <codecvt>
+#include <cctype>
 #include <limits>
 #include <stdio.h>
 
@@ -152,6 +153,8 @@ void VCP::Find(std::vector<FoundDevice>& found, std::vector<std::wstring> driver
 				if(serial.find_first_of('\\') != std::string::npos)
 					continue;
 			}
+			for(char& c : serial)
+				c = static_cast<char>(toupper(c));
 			strcpy_s(device.serial, sizeof(device.serial), serial.c_str());
 
 			// Serial number is saved, we want the COM port number now