diff --git a/mozilla/expat/xmlparse/xmlparse.c b/mozilla/expat/xmlparse/xmlparse.c
index 4b4d3e10473..c5e91ce5224 100644
--- a/mozilla/expat/xmlparse/xmlparse.c
+++ b/mozilla/expat/xmlparse/xmlparse.c
@@ -2009,8 +2009,7 @@ initializeEncoding(XML_Parser parser)
     int i;
     for (i = 0; protocolEncodingName[i]; i++) {
       if (i == sizeof(encodingBuf) - 1
-	  || protocolEncodingName[i] >= 0x80
-	  || protocolEncodingName[i] < 0) {
+	  || (protocolEncodingName[i] & ~0x7f) != 0) {
 	encodingBuf[0] = '\0';
 	break;
       }
diff --git a/mozilla/parser/expat/lib/xmlparse.c b/mozilla/parser/expat/lib/xmlparse.c
index 4b4d3e10473..c5e91ce5224 100644
--- a/mozilla/parser/expat/lib/xmlparse.c
+++ b/mozilla/parser/expat/lib/xmlparse.c
@@ -2009,8 +2009,7 @@ initializeEncoding(XML_Parser parser)
     int i;
     for (i = 0; protocolEncodingName[i]; i++) {
       if (i == sizeof(encodingBuf) - 1
-	  || protocolEncodingName[i] >= 0x80
-	  || protocolEncodingName[i] < 0) {
+	  || (protocolEncodingName[i] & ~0x7f) != 0) {
 	encodingBuf[0] = '\0';
 	break;
       }