diff --git a/Python/ast.c b/Python/ast.c
index dde0d04..93334dc 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -2879,7 +2879,7 @@
 parsestr(const char *s, const char *encoding)
 {
 	size_t len;
-	int quote = *s;
+	int quote = Py_CHARMASK(*s);
 	int rawmode = 0;
 	int need_encoding;
 	int unicode = 0;
diff --git a/Python/dynload_aix.c b/Python/dynload_aix.c
index 03ecc07..7a604f2 100644
--- a/Python/dynload_aix.c
+++ b/Python/dynload_aix.c
@@ -144,7 +144,7 @@
 		    if (nerr == load_errtab[j].errNo && load_errtab[j].errstr)
 			ERRBUF_APPEND(load_errtab[j].errstr);
 		}
-		while (isdigit(*message[i])) message[i]++ ; 
+		while (isdigit(Py_CHARMASK(*message[i]))) message[i]++ ; 
 		ERRBUF_APPEND(message[i]);
 		ERRBUF_APPEND("\n");
 	}
diff --git a/Python/getargs.c b/Python/getargs.c
index 16f156f..23b91fd 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -166,7 +166,7 @@
 			if (level == 0) {
 				if (c == 'O')
 					max++;
-				else if (isalpha(c)) {
+				else if (isalpha(Py_CHARMASK(c))) {
 					if (c != 'e') /* skip encoded */
 						max++;
 				} else if (c == '|')
@@ -255,7 +255,7 @@
 		}
 	}
 
-	if (*format != '\0' && !isalpha((int)(*format)) &&
+	if (*format != '\0' && !isalpha(Py_CHARMASK((*format))) &&
 	    *format != '(' &&
 	    *format != '|' && *format != ':' && *format != ';') {
 		PyErr_Format(PyExc_SystemError,
@@ -347,7 +347,7 @@
 		}
 		else if (c == ':' || c == ';' || c == '\0')
 			break;
-		else if (level == 0 && isalpha(c))
+		else if (level == 0 && isalpha(Py_CHARMASK(c)))
 			n++;
 	}
 	
@@ -1223,7 +1223,7 @@
 	min = -1;
 	max = 0;
 	while ((i = *format++) != '\0') {
-		if (isalpha(i) && i != 'e') {
+		if (isalpha(Py_CHARMASK(i)) && i != 'e') {
 			max++;
 			if (*p == NULL) {
 				PyErr_SetString(PyExc_RuntimeError,