diff --git a/src/unicode.cpp b/src/unicode.cpp
index 6b3b2dbe7d..cc7030d1dd 100644
--- a/src/unicode.cpp
+++ b/src/unicode.cpp
@@ -499,6 +499,7 @@
     return bpe_offsets;
 }
 
+#if 0
 // use std::wregex to split the text
 static std::vector<size_t> unicode_regex_split_stl(const std::wstring & wtext, const std::wstring & regex_expr, const std::vector<size_t> & offsets) {
     std::wregex expr(regex_expr);
@@ -528,6 +529,7 @@
 
     return bpe_offsets;
 }
+#endif
 
 // use std::regex to split the text
 static std::vector<size_t> unicode_regex_split_stl(const std::string & text, const std::string & regex_expr, const std::vector<size_t> & offsets) {
@@ -818,20 +820,22 @@
                 //printf("regex_expr_collapsed: %s\n", regex_expr_collapsed.c_str());
                 bpe_offsets = unicode_regex_split_stl(text_collapsed, regex_expr_collapsed, bpe_offsets);
             } else {
-                // no unicode category used, we can use std::wregex directly
-                const std::wstring wregex_expr = unicode_wstring_from_utf8(regex_expr);
+                fprintf(stderr, "Only use utf-8");
+                std::abort();
+                // // no unicode category used, we can use std::wregex directly
+                // const std::wstring wregex_expr = unicode_wstring_from_utf8(regex_expr);
 
-                // std::wregex \s does not mach non-ASCII whitespaces, using 0x0B as fallback
-                std::wstring wtext(cpts.begin(), cpts.end());
-                for (size_t i = 0; i < wtext.size(); ++i) {
-                    if (wtext[i] > 0x7F && unicode_cpt_flags_from_cpt(wtext[i]).is_whitespace) {
-                        wtext[i] = 0x0B;
-                    }
-                }
+                // // std::wregex \s does not mach non-ASCII whitespaces, using 0x0B as fallback
+                // std::wstring wtext(cpts.begin(), cpts.end());
+                // for (size_t i = 0; i < wtext.size(); ++i) {
+                //     if (wtext[i] > 0x7F && unicode_cpt_flags_from_cpt(wtext[i]).is_whitespace) {
+                //         wtext[i] = 0x0B;
+                //     }
+                // }
 
-                //printf("text: %s\n", text.c_str());
-                //printf("regex_expr: %s\n", regex_expr.c_str());
-                bpe_offsets = unicode_regex_split_stl(wtext, wregex_expr, bpe_offsets);
+                // //printf("text: %s\n", text.c_str());
+                // //printf("regex_expr: %s\n", regex_expr.c_str());
+                // bpe_offsets = unicode_regex_split_stl(wtext, wregex_expr, bpe_offsets);
             }
         } catch (std::regex_error & e) {
             fprintf(stderr, "Failed to process regex: '%s'\n", regex_expr.c_str());