diff --git a/src/command.cpp b/src/command.cpp
index 2a557764c5..29c1289b9c 100644
--- a/src/command.cpp
+++ b/src/command.cpp
@@ -1180,7 +1180,7 @@ CommandCost DoCommandPInternal(TileIndex tile, uint32_t p1, uint32_t p2, uint64_
 				std::vector<uint8_t> buffer;
 				CommandSerialisationBuffer serialiser(buffer, SHRT_MAX);
 				aux_data->Serialise(serialiser);
-				aux_str = FormatArrayAsHex(buffer);
+				aux_str = FormatArrayAsHex(buffer, false);
 			}
 			std::string text_buf;
 			if (text != nullptr) {
diff --git a/src/network/network.cpp b/src/network/network.cpp
index 7ad6d6a8d4..fd4f191d35 100644
--- a/src/network/network.cpp
+++ b/src/network/network.cpp
@@ -219,7 +219,7 @@ std::string GenerateCompanyPasswordHash(const std::string &password, const std::
 	checksum.Append(salted_password_string.data(), salted_password_string.size());
 	checksum.Finish(digest);
 
-	return FormatArrayAsHex(digest);
+	return FormatArrayAsHex(digest, false);
 }
 
 /**
@@ -1375,7 +1375,7 @@ std::string NetworkGenerateRandomKeyString(uint bytes)
 	uint8_t *key = AllocaM(uint8_t, bytes);
 	RandomBytesWithFallback({ key, bytes });
 
-	return FormatArrayAsHex({key, bytes});
+	return FormatArrayAsHex({key, bytes}, false);
 }
 
 /** This tries to launch the network for a given OS */
diff --git a/src/string_func.h b/src/string_func.h
index edb27d8f00..87522c0eb7 100644
--- a/src/string_func.h
+++ b/src/string_func.h
@@ -41,7 +41,7 @@ int CDECL vseprintf(char *str, const char *last, const char *format, va_list ap)
 std::string CDECL stdstr_fmt(const char *str, ...) WARN_FORMAT(1, 2);
 std::string stdstr_vfmt(const char *str, va_list va) WARN_FORMAT(1, 0);
 
-std::string FormatArrayAsHex(std::span<const uint8_t> data, bool upper_case = false);
+std::string FormatArrayAsHex(std::span<const uint8_t> data, bool upper_case = true);
 
 char *StrMakeValidInPlace(char *str, const char *last, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK) NOACCESS(2);
 [[nodiscard]] std::string StrMakeValid(std::string_view str, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK);
diff --git a/src/tests/string_func.cpp b/src/tests/string_func.cpp
index e0ea052cbc..a5cd29100d 100644
--- a/src/tests/string_func.cpp
+++ b/src/tests/string_func.cpp
@@ -341,7 +341,9 @@ TEST_CASE("FormatArrayAsHex")
 {
 	CHECK(FormatArrayAsHex(std::array<uint8_t, 0>{}) == "");
 	CHECK(FormatArrayAsHex(std::array<uint8_t, 1>{0x12}) == "12");
-	CHECK(FormatArrayAsHex(std::array<uint8_t, 4>{0x13, 0x38, 0x42, 0xAF}) == "133842af");
+	CHECK(FormatArrayAsHex(std::array<uint8_t, 4>{0x13, 0x38, 0x42, 0xAF}) == "133842AF");
+	CHECK(FormatArrayAsHex(std::array<uint8_t, 4>{0x13, 0x38, 0x42, 0xAF}, true) == "133842AF");
+	CHECK(FormatArrayAsHex(std::array<uint8_t, 4>{0x13, 0x38, 0x42, 0xAF}, false) == "133842af");
 }
 
 TEST_CASE("ConvertHexToBytes")