diff --git a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test4/test4.cpp b/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test4/test4.cpp
index 53a45ed008a491..39bdbb1a11d0f0 100644
--- a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test4/test4.cpp
+++ b/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test4/test4.cpp
@@ -224,6 +224,23 @@ PALTEST(locale_info_MultiByteToWideChar_test4_paltest_multibytetowidechar_test4,
         free(wideBuffer);
     }
 
+    {
+        // U+6F22 — code unit > U+00FF catches long-code-path bugs that move
+        // only the low byte instead of performing a full 16-bit byte swap.
+        const char utf8[] = "\xE6\xBC\xA2";
+        WCHAR wide[1] = { 0 };
+        size_t n = minipal_convert_utf8_to_utf16(utf8, sizeof(utf8) - 1, (CHAR16_T*)wide, 1, 0);
+        if (n != 1 || wide[0] != 0x6F22)
+            Fail("utf8->utf16 produced 0x%04x (n=%zu)\n", wide[0], n);
+
+#if BIGENDIAN
+        wide[0] = 0;
+        n = minipal_convert_utf8_to_utf16(utf8, sizeof(utf8) - 1, (CHAR16_T*)wide, 1, MINIPAL_TREAT_AS_LITTLE_ENDIAN);
+        if (n != 1 || wide[0] != 0x226F)
+            Fail("treat-as-LE utf8->utf16 produced 0x%04x (n=%zu)\n", wide[0], n);
+#endif
+    }
+
 #if BIGENDIAN
     {
         const char* ascii = "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456";
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test5/test5.cpp b/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test5/test5.cpp
index 697730b9dbd026..115faf95bfd2d3 100644
--- a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test5/test5.cpp
+++ b/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test5/test5.cpp
@@ -148,6 +148,27 @@ PALTEST(locale_info_WideCharToMultiByte_test5_paltest_widechartomultibyte_test5,
         free(utf8Buffer);
     }
 
+    {
+        // U+6F22 — code unit > U+00FF catches long-code-path bugs that move
+        // only the low byte instead of performing a full 16-bit byte swap.
+        const WCHAR srcNative[1] = { 0x6F22 };
+        CHAR utf8[4] = { 0 };
+        size_t n = minipal_convert_utf16_to_utf8((const CHAR16_T*)srcNative, 1, utf8, sizeof(utf8), 0);
+        if (n != 3 || memcmp(utf8, "\xE6\xBC\xA2", 3) != 0)
+            Fail("utf16->utf8 produced %02x %02x %02x (n=%zu)\n",
+                (unsigned char)utf8[0], (unsigned char)utf8[1], (unsigned char)utf8[2], n);
+
+#if BIGENDIAN
+        // Stored little-endian (22 6F) reads as BE word 0x226F.
+        const WCHAR srcLE[1] = { 0x226F };
+        memset(utf8, 0, sizeof(utf8));
+        n = minipal_convert_utf16_to_utf8((const CHAR16_T*)srcLE, 1, utf8, sizeof(utf8), MINIPAL_TREAT_AS_LITTLE_ENDIAN);
+        if (n != 3 || memcmp(utf8, "\xE6\xBC\xA2", 3) != 0)
+            Fail("treat-as-LE utf16->utf8 produced %02x %02x %02x (n=%zu)\n",
+                (unsigned char)utf8[0], (unsigned char)utf8[1], (unsigned char)utf8[2], n);
+#endif
+    }
+
 #if BIGENDIAN
     {
         const char* expected = "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456";
diff --git a/src/native/minipal/utf8.c b/src/native/minipal/utf8.c
index e0b25fce415473..c1a3d3b9d37a31 100644
--- a/src/native/minipal/utf8.c
+++ b/src/native/minipal/utf8.c
@@ -983,7 +983,7 @@ static size_t GetChars(UTF8Encoding* self, unsigned char* bytes, size_t byteCoun
         }
 #if BIGENDIAN
         if (self->treatAsLE)
-            *pTarget = ((CHAR16_T)ch)<<8;
+            *pTarget = (((CHAR16_T)ch) << 8 | ((CHAR16_T)ch) >> 8);
         else
 #endif
         *pTarget = (CHAR16_T)ch;
@@ -1438,7 +1438,7 @@ static size_t GetBytes(UTF8Encoding* self, CHAR16_T* chars, size_t charCount, un
         // compiling "ch = *pSrc++;", so rather use "ch = *pSrc; pSrc++;" instead
 #if BIGENDIAN
         if (self->treatAsLE)
-            ch = (*pSrc) >> 8;
+            ch = (CHAR16_T)(((*pSrc) >> 8) | ((*pSrc) << 8));
         else
 #endif
         ch = *pSrc;
@@ -1581,7 +1581,7 @@ static size_t GetBytes(UTF8Encoding* self, CHAR16_T* chars, size_t charCount, un
             {
 #if BIGENDIAN
                 if (self->treatAsLE)
-                    ch = (*pSrc) >> 8;
+                    ch = (CHAR16_T)(((*pSrc) >> 8) | ((*pSrc) << 8));
                 else
 #endif
                 ch = *pSrc;
@@ -1619,7 +1619,7 @@ static size_t GetBytes(UTF8Encoding* self, CHAR16_T* chars, size_t charCount, un
         {
 #if BIGENDIAN
             if (self->treatAsLE)
-                ch = (*pSrc) >> 8;
+                ch = (CHAR16_T)(((*pSrc) >> 8) | ((*pSrc) << 8));
             else
 #endif
             ch = *pSrc;
@@ -1635,7 +1635,7 @@ static size_t GetBytes(UTF8Encoding* self, CHAR16_T* chars, size_t charCount, un
             {
 #if BIGENDIAN
                 if (self->treatAsLE)
-                    ch = (*pSrc) >> 8;
+                    ch = (CHAR16_T)(((*pSrc) >> 8) | ((*pSrc) << 8));
                 else
 #endif
                 ch = *pSrc;
@@ -1652,10 +1652,7 @@ static size_t GetBytes(UTF8Encoding* self, CHAR16_T* chars, size_t charCount, un
                 ch = *(int*)pSrc;
                 int chc = *(int*)(pSrc + 2);
 #if BIGENDIAN
-                if (self->treatAsLE){
-                    if (((ch | chc) & (int)0x80FF80FF) != 0) goto LongCodeWithMask;
-                }
-                else
+                if (((ch | chc) & (int)0x80FF80FF) != 0) goto LongCodeWithMask;
 #else
                 if (((ch | chc) & (int)0xFF80FF80) != 0) goto LongCodeWithMask;
 #endif