diff --git a/source/code/DialogBox.hpp b/source/code/DialogBox.hpp
index 04ad0cf..76701f8 100644
--- a/source/code/DialogBox.hpp
+++ b/source/code/DialogBox.hpp
@@ -32,9 +32,9 @@ http://www.blockattack.net
 #include "global.hpp"
 
 struct VirtualKeyboard {
-	const std::string leftChar = "‹";
-	const std::string rightChar = "›";
-	const std::string backspace = "«";
+	const std::string leftChar = "\xe2\x80\xb9"; //UTF-8 for left arrow symbol (U+2039)
+	const std::string rightChar = "\xe2\x80\xba"; //UTF-8 for right arrow symbol (U+203A)
+	const std::string backspace = "\xc2\xab"; //UTF-8 for LEFT-POINTING DOUBLE ANGLE QUOTATION MARK (U+00AB)
 	std::string alphabet = std::string(_("ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 	                                     "abcdefghijklmnopqrstuvwxyz"
 	                                     ".,:!?+_^@#%&=*")) + leftChar + rightChar + backspace;
diff --git a/source/misc/lint/runLint.sh b/source/misc/lint/runLint.sh
index 5e49ccf..2299e39 100644
--- a/source/misc/lint/runLint.sh
+++ b/source/misc/lint/runLint.sh
@@ -6,8 +6,10 @@ TMPFILE=$(mktemp /tmp/sago-lint.XXXXXX)
 find ./source/code/ -name "*.cpp" -not -path "./source/code/Libs/*" | xargs --no-run-if-empty grep --with-filename --line-number "^  " >> ${TMPFILE}  || true
 find ./source/code/ -name "*.h*" -not -path "./source/code/Libs/*" | xargs --no-run-if-empty grep --with-filename --line-number "^  " >> ${TMPFILE}  || true
 
+
+
 if [ -s "$TMPFILE" ]
-then 
+then
 echo "In the following places the lines are indended with spaces. This project uses tabs for indentation."
 echo "The rule applies to comments too although the check can be bypassed by using either C++ style comments or \" *\" to start a line (Doxygen comments)"
 cat "$TMPFILE"
@@ -17,4 +19,19 @@ rm "$TMPFILE"
 exit 1
 fi
 
+>> "${TMPFILE}"
+export LANG=C
+find ./source/code/ -name "*.cpp" -not -path "./source/code/Libs/*" | xargs --no-run-if-empty grep --with-filename --line-number -aRnP '[\x80-\xFF]' >> ${TMPFILE}  || true
+find ./source/code/ -name "*.h*" -not -path "./source/code/Libs/*" | xargs --no-run-if-empty grep --with-filename --line-number -aRnP '[\x80-\xFF]' >> ${TMPFILE}  || true
+
+if [ -s "$TMPFILE" ]
+then
+echo "In the following places the lines contain non-ASCII characters."
+cat "$TMPFILE"
+echo ""
+echo "Validation failed"
 rm "$TMPFILE"
+exit 1
+fi
+
+rm "$TMPFILE"
\ No newline at end of file