diff --git a/mozilla/extensions/transformiix/source/base/TxString.cpp b/mozilla/extensions/transformiix/source/base/TxString.cpp
index e18484b66ee..299bcd94445 100644
--- a/mozilla/extensions/transformiix/source/base/TxString.cpp
+++ b/mozilla/extensions/transformiix/source/base/TxString.cpp
@@ -170,7 +170,7 @@ PRInt32 String::indexOf(UNICODE_CHAR aData,
 
   PRInt32 searchIndex = aOffset;
 
-  while (searchIndex < mLength) {
+  while (searchIndex < (PRInt32)mLength) {
     if (mBuffer[searchIndex] == aData) {
       return searchIndex;
     }
diff --git a/mozilla/extensions/transformiix/source/xpath/ExprLexer.cpp b/mozilla/extensions/transformiix/source/xpath/ExprLexer.cpp
index ba9c764d677..69a807b35c5 100644
--- a/mozilla/extensions/transformiix/source/xpath/ExprLexer.cpp
+++ b/mozilla/extensions/transformiix/source/xpath/ExprLexer.cpp
@@ -337,7 +337,7 @@ void ExprLexer::parse(const String& pattern)
       case D_QUOTE :
         start=iter;
         iter = pattern.indexOf(ch, (PRInt32)start + 1);
-        if (iter == kNotFound) {
+        if ((PRInt32)iter == kNotFound) {
           // XXX Error reporting "unclosed literal"
           errorPos = start;
           errorCode = ERROR_UNCLOSED_LITERAL;
diff --git a/mozilla/extensions/transformiix/source/xpath/StringFunctionCall.cpp b/mozilla/extensions/transformiix/source/xpath/StringFunctionCall.cpp
index 1a874c534c1..c6635c57fe8 100644
--- a/mozilla/extensions/transformiix/source/xpath/StringFunctionCall.cpp
+++ b/mozilla/extensions/transformiix/source/xpath/StringFunctionCall.cpp
@@ -219,10 +219,11 @@ ExprResult* StringFunctionCall::evaluate(txIEvalContext* aContext)
             evaluateToString((Expr*)iter.next(), aContext, oldChars);
             evaluateToString((Expr*)iter.next(), aContext, newChars);
             PRUint32 i;
+            PRInt32 newCharsLength = (PRInt32)newChars.length();
             for (i = 0; i < src.length(); i++) {
                 PRInt32 idx = oldChars.indexOf(src.charAt(i));
                 if (idx != kNotFound) {
-                    if (idx < newChars.length())
+                    if (idx < newCharsLength)
                         dest.append(newChars.charAt((PRUint32)idx));
                 }
                 else {