diff --git a/libraries/libstratosphere/source/os/impl/os_utility.cpp b/libraries/libstratosphere/source/os/impl/os_utility.cpp
index 3a0f709f9..0498b469e 100644
--- a/libraries/libstratosphere/source/os/impl/os_utility.cpp
+++ b/libraries/libstratosphere/source/os/impl/os_utility.cpp
@@ -18,25 +18,87 @@
 
 namespace ams::os::impl {
 
-    void ExpandUnsignedValueToAscii(char *dst, u64 value) {
-        /* Determine size needed. */
-        constexpr size_t SizeNeeded = (BITSIZEOF(value) / 4) * sizeof(char);
+    namespace {
 
-        /* Write null-terminator. */
-        dst[SizeNeeded] = '\x00';
+        constexpr void ExpandUnsignedValueToAsciiImpl(char *dst, u64 value) {
+            /* Determine size needed. */
+            constexpr size_t SizeNeeded = (BITSIZEOF(value) / 4) * sizeof(char);
 
-        /* Write characters. */
-        for (size_t i = 0; i < SizeNeeded; ++i) {
-            /* Determine current character. */
-            const auto nybble = (value & 0xF);
-            const char cur_c  = (nybble < 10) ? ('0' + nybble) : ('A' + nybble - 10);
+            /* Write null-terminator. */
+            dst[SizeNeeded] = '\x00';
 
-            /* Write current character. */
-            dst[SizeNeeded - 1 - i] = cur_c;
+            /* Write characters. */
+            for (size_t i = 0; i < SizeNeeded; ++i) {
+                /* Determine current character. */
+                const auto nybble = (value & 0xF);
+                const char cur_c  = (nybble < 10) ? ('0' + nybble) : ('A' + nybble - 10);
 
-            /* Shift to next nybble. */
-            value >>= 4;
+                /* Write current character. */
+                dst[SizeNeeded - 1 - i] = cur_c;
+
+                /* Shift to next nybble. */
+                value >>= 4;
+            }
         }
+
     }
 
+    void ExpandUnsignedValueToAscii(char *dst, u64 value) {
+        return ExpandUnsignedValueToAsciiImpl(dst, value);
+    }
+
+    /* Test correctness. */
+    #if 0
+    namespace {
+
+        consteval bool TestExpandUnsignedValueToAsciiImpl(const char *expected, u64 value) {
+            /* Create buffer. */
+            char buffer[17] = {
+                '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC', '\xCC'
+            };
+
+            /* Validate buffer is initially garbage. */
+            for (size_t i = 0; i < util::size(buffer); ++i) {
+                if (buffer[i] != '\xCC') {
+                    return false;
+                }
+            }
+
+            /* Expand the value into the buffer. */
+            ExpandUnsignedValueToAsciiImpl(buffer, value);
+
+            /* Verify the result. */
+            for (size_t i = 0; i < util::size(buffer); ++i) {
+                if (buffer[i] != expected[i]) {
+                    return false;
+                }
+            }
+
+            /* Verify null-termination. */
+            if (buffer[util::size(buffer) - 1] != 0) {
+                return false;
+            }
+
+            return true;
+        }
+
+        #define DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(v) static_assert(TestExpandUnsignedValueToAsciiImpl( #v , UINT64_C(0x##v)))
+
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(0000000000000000);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(FFFFFFFFFFFFFFFF);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(FFFFFFFF00000000);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(00000000FFFFFFFF);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(FFFF0000FFFF0000);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(0000FFFF0000FFFF);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(F0F0F0F0F0F0F0F0);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(0F0F0F0F0F0F0F0F);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(0123456789ABCDEF);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(FEDCBA9876543210);
+        DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL(A5A5A5A5A5A5A5A5);
+
+        #undef DO_TEST_EXPAND_UNSIGNED_VALUE_TO_ASCII_IMPL
+
+    }
+    #endif
+
 }