diff --git a/libbb/process_escape_sequence.c b/libbb/process_escape_sequence.c
index e6b5fc995..9b57ff99e 100644
--- a/libbb/process_escape_sequence.c
+++ b/libbb/process_escape_sequence.c
@@ -52,6 +52,8 @@ char bb_process_escape_sequence(const char **ptr)
 			r = n * 16 + hextobin(*q);
 		} else if (isodigit(*q)) {
 			r = n * 8 + octtobin(*q);
+		} else {
+			break;
 		}
 		if (r <= UCHAR_MAX) {
 			n = r;