diff --git a/src/libespeak-ng/compiledict.c b/src/libespeak-ng/compiledict.c
index d84d42cd..50e7726b 100644
--- a/src/libespeak-ng/compiledict.c
+++ b/src/libespeak-ng/compiledict.c
@@ -1369,6 +1369,7 @@ static espeak_ng_STATUS compile_dictrules(FILE *f_in, FILE *f_out, char *fname_t
 			if (compile_mode == 2) {
 				// end of the character replacements section
 				fwrite(&n_rules, 1, 4, f_out); // write a zero word to terminate the replacemenmt list
+				fputc(RULE_GROUP_END, f_out);
 				compile_mode = 0;
 			}
 
@@ -1447,33 +1448,23 @@ static espeak_ng_STATUS compile_dictrules(FILE *f_in, FILE *f_out, char *fname_t
 			}
 			break;
 		case 2: //  .replace
-		{
-			int replace1;
-			int replace2;
-			char *p;
+			p = (unsigned char *)buf;
 
-			p = buf;
-			replace1 = 0;
-			replace2 = 0;
 			while (isspace2(*p)) p++;
-			ix = 0;
-			while ((unsigned char)(*p) > 0x20) { // not space or zero-byte
-				p += utf8_in(&c, p);
-				replace1 += (c << ix);
-				ix += 16;
+			if ((unsigned char)(*p) > 0x20) {
+				while ((unsigned char)(*p) > 0x20) { // not space or zero-byte
+					fputc(*p, f_out);
+					p++;
+				}
+				fputc(0, f_out);
+
+				while (isspace2(*p)) p++;
+				while ((unsigned char)(*p) > 0x20) {
+					fputc(*p, f_out);
+					p++;
+				}
+				fputc(0, f_out);
 			}
-			while (isspace2(*p)) p++;
-			ix = 0;
-			while ((unsigned char)(*p) > 0x20) {
-				p += utf8_in(&c, p);
-				replace2 += (c << ix);
-				ix += 16;
-			}
-			if (replace1 != 0) {
-				Write4Bytes(f_out, replace1); // write as little-endian
-				Write4Bytes(f_out, replace2); // if big-endian, reverse the bytes in LoadDictionary()
-			}
-		}
 			break;
 		}
 	}
diff --git a/src/libespeak-ng/dictionary.c b/src/libespeak-ng/dictionary.c
index 11962952..6194ef14 100644
--- a/src/libespeak-ng/dictionary.c
+++ b/src/libespeak-ng/dictionary.c
@@ -149,20 +149,11 @@ static void InitGroups(Translator *tr)
 
 		if (p[0] == RULE_REPLACEMENTS) {
 			p = (char *)(((intptr_t)p+4) & ~3); // advance to next word boundary
-			tr->langopts.replace_chars = (unsigned int *)p;
+			tr->langopts.replace_chars = (unsigned char *)p;
 			while (*(unsigned int *)p != 0)
-				p += 8; // find the end of the replacement list, each entry is 2 words.
-			p += 4;
-
-#ifdef ARCH_BIG
-			pw = (unsigned int *)(tr->langopts.replace_chars);
-			while (*pw != 0) {
-				*pw = Reverse4Bytes(*pw);
-				pw++;
-				*pw = Reverse4Bytes(*pw);
-				pw++;
-			}
-#endif
+				p++;
+			while (*p != RULE_GROUP_END) p++;
+			p++;
 			continue;
 		}
 
diff --git a/src/libespeak-ng/translate.c b/src/libespeak-ng/translate.c
index 51b3684f..a586b2d3 100644
--- a/src/libespeak-ng/translate.c
+++ b/src/libespeak-ng/translate.c
@@ -1790,15 +1790,38 @@ static int EmbeddedCommand(unsigned int *source_index_out)
 	return 1;
 }
 
+static const char *
+FindReplacementChars(Translator *tr, unsigned int c, unsigned int nextc, bool *ignore_next) {
+	unsigned int uc = 0;
+	const char *from = (const char *)tr->langopts.replace_chars;
+	while (*(unsigned int *)from != 0) {
+		from += utf8_in((int *)&uc, from);
+		if (c == uc) {
+			if (*from == 0) return from + 1;
+			from += utf8_in((int *)&uc, from);
+			if (*from == 0 && uc == (unsigned int)towlower2(nextc, tr)) {
+				*ignore_next = true;
+				return from + 1;
+			}
+		}
+
+		// replacement 'from' string (skip the remaining part, if any)
+		while (*from != '\0') from++;
+		from++;
+
+		// replacement 'to' string
+		while (*from != '\0') from++;
+		from++;
+	}
+	return NULL;
+}
+
 // handle .replace rule in xx_rules file
 static int SubstituteChar(Translator *tr, unsigned int c, unsigned int next_in, int *insert, int *wordflags)
 {
-	int ix;
-	unsigned int word;
 	unsigned int new_c, c2 = ' ', c_lower;
 	int upper_case = 0;
 	static bool ignore_next = false;
-	const unsigned int *replace_chars;
 
 	if (ignore_next) {
 		ignore_next = false;
@@ -1806,7 +1829,7 @@ static int SubstituteChar(Translator *tr, unsigned int c, unsigned int next_in,
 	}
 	if (c == 0) return 0;
 
-	if ((replace_chars = tr->langopts.replace_chars) == NULL)
+	if (tr->langopts.replace_chars == NULL)
 		return c;
 
 	// there is a list of character codes to be substituted with alternative codes
@@ -1816,32 +1839,18 @@ static int SubstituteChar(Translator *tr, unsigned int c, unsigned int next_in,
 		upper_case = 1;
 	}
 
-	new_c = 0;
-	for (ix = 0; (word = replace_chars[ix]) != 0; ix += 2) {
-		if (c_lower == (word & 0xffff)) {
-			if ((word >> 16) == 0) {
-				new_c = replace_chars[ix+1];
-				break;
-			}
-			if ((word >> 16) == (unsigned int)towlower2(next_in, tr)) {
-				new_c = replace_chars[ix+1];
-				ignore_next = true;
-				break;
-			}
-		}
-	}
-
-	if (new_c == 0)
+	const char *to = FindReplacementChars(tr, c_lower, next_in, &ignore_next);
+	if (to == NULL)
 		return c; // no substitution
 
-	if (new_c & 0xffe00000) {
+	to += utf8_in((int *)&new_c, to);
+	if (*to != 0) {
 		// there is a second character to be inserted
 		// don't convert the case of the second character unless the next letter is also upper case
-		c2 = new_c >> 16;
+		to += utf8_in((int *)&c2, to);
 		if (upper_case && iswupper(next_in))
 			c2 = ucd_toupper(c2);
 		*insert = c2;
-		new_c &= 0xffff;
 	}
 
 	if (upper_case)
diff --git a/src/libespeak-ng/translate.h b/src/libespeak-ng/translate.h
index b2cdf3e8..fb586c15 100644
--- a/src/libespeak-ng/translate.h
+++ b/src/libespeak-ng/translate.h
@@ -556,7 +556,7 @@ typedef struct {
 	bool textmode;          // the meaning of FLAG_TEXTMODE is reversed (to save data when *_list file is compiled)
 	char dotless_i;         // uses letter U+0131
 	int listx;    // compile *_listx after *list
-	const unsigned int *replace_chars;      // characters to be substitutes
+	const unsigned char *replace_chars;      // characters to be substitutes
 	int our_alphabet;           // offset for main alphabet (if not set in letter_bits_offset)
 	int alt_alphabet;       // offset for another language to recognize
 	int alt_alphabet_lang;  // language for the alt_alphabet