diff --git a/src/csutil.cxx b/src/csutil.cxx
--- a/src/csutil.cxx
+++ b/src/csutil.cxx
@@ -90,21 +90,17 @@
 #else
 #ifndef MOZILLA_CLIENT
 #include "utf_info.hxx"
 #define UTF_LST_LEN (sizeof(utf_lst) / (sizeof(unicode_info)))
 #endif
 #endif
 
 #ifdef MOZILLA_CLIENT
-#include "nsCOMPtr.h"
-#include "nsUnicharUtils.h"
-#include "mozilla/Encoding.h"
-
-using namespace mozilla;
+#include "mozHunspellRLBoxGlue.h"
 #endif
 
 struct unicode_info2 {
   char cletter;
   unsigned short cupper;
   unsigned short clower;
 };
 
@@ -2277,101 +2273,18 @@ struct cs_info* get_current_cs(const std
                      "error: unknown encoding %s: using %s as fallback\n", es.c_str(),
                      encds[0].enc_name);
     ccs = encds[0].cs_table;
   }
 
   return ccs;
 }
 #else
-// XXX This function was rewritten for mozilla. Instead of storing the
-// conversion tables static in this file, create them when needed
-// with help the mozilla backend.
 struct cs_info* get_current_cs(const std::string& es) {
-  struct cs_info* ccs = new cs_info[256];
-  // Initialze the array with dummy data so that we wouldn't need
-  // to return null in case of failures.
-  for (int i = 0; i <= 0xff; ++i) {
-    ccs[i].ccase = false;
-    ccs[i].clower = i;
-    ccs[i].cupper = i;
-  }
-
-  auto encoding = Encoding::ForLabelNoReplacement(es);
-  if (!encoding) {
-    return ccs;
-  }
-  auto encoder = encoding->NewEncoder();
-  auto decoder = encoding->NewDecoderWithoutBOMHandling();
-
-  for (unsigned int i = 0; i <= 0xff; ++i) {
-    bool success = false;
-    // We want to find the upper/lowercase equivalents of each byte
-    // in this 1-byte character encoding.  Call our encoding/decoding
-    // APIs separately for each byte since they may reject some of the
-    // bytes, and we want to handle errors separately for each byte.
-    uint8_t lower, upper;
-    do {
-      if (i == 0)
-        break;
-      uint8_t source = uint8_t(i);
-      char16_t uni[2];
-      char16_t uniCased;
-      uint8_t destination[4];
-      auto src1 = MakeSpan(&source, 1);
-      auto dst1 = MakeSpan(uni);
-      auto src2 = MakeSpan(&uniCased, 1);
-      auto dst2 = MakeSpan(destination);
-
-      uint32_t result;
-      size_t read;
-      size_t written;
-      Tie(result, read, written) =
-        decoder->DecodeToUTF16WithoutReplacement(src1, dst1, true);
-      if (result != kInputEmpty || read != 1 || written != 1) {
-        break;
-      }
-
-      uniCased = ToLowerCase(uni[0]);
-      Tie(result, read, written) =
-        encoder->EncodeFromUTF16WithoutReplacement(src2, dst2, true);
-      if (result != kInputEmpty || read != 1 || written != 1) {
-        break;
-      }
-      lower = destination[0];
-
-      uniCased = ToUpperCase(uni[0]);
-      Tie(result, read, written) =
-        encoder->EncodeFromUTF16WithoutReplacement(src2, dst2, true);
-      if (result != kInputEmpty || read != 1 || written != 1) {
-        break;
-      }
-      upper = destination[0];
-
-      success = true;
-    } while (0);
-
-    encoding->NewEncoderInto(*encoder);
-    encoding->NewDecoderWithoutBOMHandlingInto(*decoder);
-
-    if (success) {
-      ccs[i].cupper = upper;
-      ccs[i].clower = lower;
-    } else {
-      ccs[i].cupper = i;
-      ccs[i].clower = i;
-    }
-
-    if (ccs[i].clower != (unsigned char)i)
-      ccs[i].ccase = true;
-    else
-      ccs[i].ccase = false;
-  }
-
-  return ccs;
+  return moz_hunspell_GetCurrentCS(es.c_str());
 }
 #endif
 
 // primitive isalpha() replacement for tokenization
 std::string get_casechars(const char* enc) {
   struct cs_info* csconv = get_current_cs(enc);
   std::string expw;
   for (int i = 0; i <= 255; ++i) {
@@ -2455,34 +2368,34 @@ unsigned short unicodetoupper(unsigned s
   // There are a dotless lower case i pair of upper `I',
   // and an upper I with dot pair of lower `i'.
   if (c == 0x0069 && ((langnum == LANG_az) || (langnum == LANG_tr) || (langnum == LANG_crh)))
     return 0x0130;
 #ifdef OPENOFFICEORG
   return static_cast<unsigned short>(u_toupper(c));
 #else
 #ifdef MOZILLA_CLIENT
-  return ToUpperCase((char16_t)c);
+  return moz_hunspell_ToUpperCase((char16_t)c);
 #else
   return (utf_tbl) ? utf_tbl[c].cupper : c;
 #endif
 #endif
 }
 
 unsigned short unicodetolower(unsigned short c, int langnum) {
   // In Azeri and Turkish, I and i dictinct letters:
   // There are a dotless lower case i pair of upper `I',
   // and an upper I with dot pair of lower `i'.
   if (c == 0x0049 && ((langnum == LANG_az) || (langnum == LANG_tr) || (langnum == LANG_crh)))
     return 0x0131;
 #ifdef OPENOFFICEORG
   return static_cast<unsigned short>(u_tolower(c));
 #else
 #ifdef MOZILLA_CLIENT
-  return ToLowerCase((char16_t)c);
+  return moz_hunspell_ToLowerCase((char16_t)c);
 #else
   return (utf_tbl) ? utf_tbl[c].clower : c;
 #endif
 #endif
 }
 
 int unicodeisalpha(unsigned short c) {
 #ifdef OPENOFFICEORG
diff --git a/src/csutil.hxx b/src/csutil.hxx
--- a/src/csutil.hxx
+++ b/src/csutil.hxx
@@ -77,20 +77,16 @@
 
 #include <fstream>
 #include <string>
 #include <vector>
 #include <string.h>
 #include "w_char.hxx"
 #include "htypes.hxx"
 
-#ifdef MOZILLA_CLIENT
-#include "nscore.h"  // for mozalloc headers
-#endif
-
 // casing
 #define NOCAP 0
 #define INITCAP 1
 #define ALLCAP 2
 #define HUHCAP 3
 #define HUHINITCAP 4
 
 // default encoding and keystring