diff --git a/tools/bump_version.sh b/tools/bump_version.sh
index b69deb9b4..a45280e1f 100755
--- a/tools/bump_version.sh
+++ b/tools/bump_version.sh
@@ -58,6 +58,6 @@ case "$1" in
 esac
 
 sed -i \
-    -e "s/^\(WEECHAT_STABLE\)=.*/\1=${NEW_STABLE}/" \
-    -e "s/^\(WEECHAT_DEVEL\)=.*/\1=${NEW_DEVEL_FULL}/" \
+    -e "s/^\(WEECHAT_STABLE\)=.*/\1=\"${NEW_STABLE}\"/" \
+    -e "s/^\(WEECHAT_DEVEL\)=.*/\1=\"${NEW_DEVEL_FULL}\"/" \
     "${ROOT_DIR}/version.sh"
diff --git a/version.sh b/version.sh
index 413343a10..7e17a307b 100755
--- a/version.sh
+++ b/version.sh
@@ -39,8 +39,8 @@
 #     devel-number   the devel version as hex number ("0x04010000" for "4.1.0-dev")
 #
 
-WEECHAT_STABLE=3.8
-WEECHAT_DEVEL=4.0.0-dev
+WEECHAT_STABLE="3.8"
+WEECHAT_DEVEL="4.0.0-dev"
 
 STABLE_MAJOR=$(echo "${WEECHAT_STABLE}" | cut -d'.' -f1)
 STABLE_MINOR=$(echo "${WEECHAT_STABLE}" | cut -d'.' -f2)