diff --git a/usr/share/byobu/profiles/bashrc b/usr/share/byobu/profiles/bashrc
index 7fa07d67..1709d047 100644
--- a/usr/share/byobu/profiles/bashrc
+++ b/usr/share/byobu/profiles/bashrc
@@ -37,8 +37,9 @@ byobu_prompt_runtime() {
 	local starttime endtime duration days hours minutes seconds microseconds nanoseconds str
 	[ ! -r $BYOBU_RUN_DIR/timer.$$ ] && printf "[0.000s]" && return
 	read starttime < $BYOBU_RUN_DIR/timer.$$ 2>/dev/null || true
-	endtime=${EPOCHREALTIME/./}
-	starttime=${starttime/./}
+	# strip to non-decimal time. avoids LP: #2052610
+	endtime=${EPOCHREALTIME/[^0-9]/}
+	starttime=${starttime/[^0-9]/}
 	duration=$((endtime - starttime))
 	days=$((duration/1000000/60/60/24))
 	hours=$((duration/1000000/60/60%24))
@@ -55,7 +56,7 @@ byobu_prompt_runtime() {
 	printf "[%s] " "$str" 1>&2
 }
 # Requires Bash 4.x
-export PS0='$(printf "%s" ${EPOCHREALTIME/./} >"$BYOBU_RUN_DIR/timer.$$")'
+export PS0='$(printf "%s" ${EPOCHREALTIME/[^0-9]/} >"$BYOBU_RUN_DIR/timer.$$")'
 
 case "$BYOBU_DISTRO" in
 	"Ubuntu")