diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 74c5888..bfd5c88 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -57,6 +57,10 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <windows.h>
 #endif
 
+#ifdef HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION
+#include "pycore_fileutils.h"     // _Py_LocaleUsesNonUnicodeWchar()
+#endif
+
 /* Uncomment to display statistics on interned strings at exit
    in _PyUnicode_ClearInterned(). */
 /* #define INTERNED_STATS 1 */
@@ -2217,6 +2221,20 @@ PyUnicode_FromWideChar(const wchar_t *u, Py_ssize_t size)
     if (size == 0)
         _Py_RETURN_UNICODE_EMPTY();
 
+#ifdef HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION
+    /* Oracle Solaris uses non-Unicode internal wchar_t form for
+       non-Unicode locales and hence needs conversion to UCS-4 first. */
+    if (_Py_LocaleUsesNonUnicodeWchar()) {
+        wchar_t* converted = _Py_DecodeNonUnicodeWchar(u, size);
+        if (!converted) {
+            return NULL;
+        }
+        PyObject *unicode = _PyUnicode_FromUCS4(converted, size);
+        PyMem_Free(converted);
+        return unicode;
+    }
+#endif
+
     /* Single character Unicode objects in the Latin-1 range are
        shared when using this constructor */
     if (size == 1 && (Py_UCS4)*u < 256)
@@ -3295,6 +3313,17 @@ PyUnicode_AsWideChar(PyObject *unicode,
         res = size;
     }
     unicode_copy_as_widechar(unicode, w, size);
+
+#if HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION
+    /* Oracle Solaris uses non-Unicode internal wchar_t form for
+       non-Unicode locales and hence needs conversion first. */
+    if (_Py_LocaleUsesNonUnicodeWchar()) {
+        if (_Py_EncodeNonUnicodeWchar_InPlace(w, size) < 0) {
+            return -1;
+        }
+    }
+#endif
+
     return res;
 }
 
@@ -3321,6 +3350,17 @@ PyUnicode_AsWideCharString(PyObject *unicode,
         return NULL;
     }
     unicode_copy_as_widechar(unicode, buffer, buflen + 1);
+
+#if HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION
+    /* Oracle Solaris uses non-Unicode internal wchar_t form for
+       non-Unicode locales and hence needs conversion first. */
+    if (_Py_LocaleUsesNonUnicodeWchar()) {
+        if (_Py_EncodeNonUnicodeWchar_InPlace(buffer, (buflen + 1)) < 0) {
+            return NULL;
+        }
+    }
+#endif
+
     if (size != NULL) {
         *size = buflen;
     }