diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 5e073ee..4ca29f2 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -4837,11 +4837,11 @@
     switch (class)
     {
 	case NFA_CLASS_ALNUM:
-	    if (c >= 1 && c <= 255 && isalnum(c))
+	    if (c >= 1 && c < 128 && isalnum(c))
 		return OK;
 	    break;
 	case NFA_CLASS_ALPHA:
-	    if (c >= 1 && c <= 255 && isalpha(c))
+	    if (c >= 1 && c < 128 && isalpha(c))
 		return OK;
 	    break;
 	case NFA_CLASS_BLANK:
@@ -4861,7 +4861,7 @@
 		return OK;
 	    break;
 	case NFA_CLASS_LOWER:
-	    if (MB_ISLOWER(c))
+	    if (MB_ISLOWER(c) && c != 170 && c != 186)
 		return OK;
 	    break;
 	case NFA_CLASS_PRINT:
@@ -4869,7 +4869,7 @@
 		return OK;
 	    break;
 	case NFA_CLASS_PUNCT:
-	    if (c >= 1 && c <= 255 && ispunct(c))
+	    if (c >= 1 && c < 128 && ispunct(c))
 		return OK;
 	    break;
 	case NFA_CLASS_SPACE: