diff --git a/scripts/bump_version.sh b/scripts/bump_version.sh
index df629e9..57ade94 100755
--- a/scripts/bump_version.sh
+++ b/scripts/bump_version.sh
@@ -136,7 +136,7 @@
 [ $VERBOSE ] && echo "Bumping PROJECT_NAME in doxygen/mbedtls.doxyfile and doxygen/input/doc_mainpage.h"
 for i in doxygen/mbedtls.doxyfile doxygen/input/doc_mainpage.h;
 do
-  sed -e "s/mbed TLS v[0-9\.]\{1,\}/mbed TLS v$VERSION/g" < $i > tmp
+  sed -e "s/\\([Mm]bed TLS v\\)[0-9][0-9.]*/\\1$VERSION/g" < $i > tmp
   mv tmp $i
 done