diff --git a/docs/docs.polserver.com/pol100/corechanges.xml b/docs/docs.polserver.com/pol100/corechanges.xml
index 6323327b1..99903380a 100644
--- a/docs/docs.polserver.com/pol100/corechanges.xml
+++ b/docs/docs.polserver.com/pol100/corechanges.xml
@@ -2,9 +2,14 @@
 <ESCRIPT>
 	<header>
 		<topic>Latest Core Changes</topic>
-		<datemodified>01-18-2020</datemodified>
+		<datemodified>01-20-2020</datemodified>
 	</header>
 	<version name="POL100">
+		<entry>
+			<date>01-20-2020</date>
+			<author>Kevin:</author>
+			<change type="Fixed">Huge Performance loss in Lower/Upper String functions.</change>
+		</entry>
 		<entry>
 			<date>01-18-2020</date>
 			<author>DevGIB:</author>
diff --git a/pol-core/bscript/str.cpp b/pol-core/bscript/str.cpp
index 2f51b606b..a3e8537f9 100644
--- a/pol-core/bscript/str.cpp
+++ b/pol-core/bscript/str.cpp
@@ -404,6 +404,11 @@ std::vector<wchar_t> convertutf8( const std::string& value )
 
 void String::toUpper()
 {
+  if ( !hasUTF8Characters() )
+  {
+    Clib::mkupperASCII( value_ );
+    return;
+  }
 #ifndef WINDOWS
   std::vector<wchar_t> codes = convertutf8<wchar_t>( value_ );
   value_.clear();
@@ -438,6 +443,11 @@ void String::toUpper()
 
 void String::toLower()
 {
+  if ( !hasUTF8Characters() )
+  {
+    Clib::mklowerASCII( value_ );
+    return;
+  }
 #ifndef WINDOWS
   std::vector<wchar_t> codes = convertutf8<wchar_t>( value_ );
   value_.clear();
diff --git a/pol-core/doc/core-changes.txt b/pol-core/doc/core-changes.txt
index c11b24e8f..78c73cb18 100644
--- a/pol-core/doc/core-changes.txt
+++ b/pol-core/doc/core-changes.txt
@@ -1,4 +1,6 @@
 -- POL100 --
+01-20-2020 Kevin:
+    Fixed: Huge Performance loss in Lower/Upper String functions.
 01-18-2020 DevGIB:
   Changed: Return type of XMLFile method .appendxmlnode() now returns the created node on success.
   Changed: Return type of XMLNode method .appendxmlnode() now returns the created node on success.