1 files changed, 9 insertions, 5 deletions

diff --git a/toke.c b/toke.c
index c9206a5b70..a9b5e498e9 100644
--- a/toke.c
+++ b/toke.c
@@ -285,8 +285,8 @@ static const char* const lex_state_names[] = {
 	}
 #define UNI(f)    UNI2(f,XTERM)
 #define UNIDOR(f) UNI2(f,XTERMORDORDOR)
-#define UNIPROTO(f) { \
-	PL_last_uni = PL_oldbufptr; \
+#define UNIPROTO(f,optional) { \
+	if (optional) PL_last_uni = PL_oldbufptr; \
 	OPERATOR(f); \
 	}
 
@@ -6851,10 +6851,13 @@ Perl_yylex(pTHX)
 		    {
 			STRLEN protolen = CvPROTOLEN(cv);
 			const char *proto = CvPROTO(cv);
+			bool optional;
 			if (!protolen)
 			    TERM(FUNC0SUB);
-			while (*proto == ';')
+			if ((optional = *proto == ';'))
+			  do
 			    proto++;
+			  while (*proto == ';');
 			if (
 			    (
 			        (
@@ -6867,12 +6870,13 @@ Perl_yylex(pTHX)
 			     *proto == '\\' && proto[1] && proto[2] == '\0'
 			    )
 			)
-			    UNIPROTO(UNIOPSUB);
+			    UNIPROTO(UNIOPSUB,optional);
 			if (*proto == '\\' && proto[1] == '[') {
 			    const char *p = proto + 2;
 			    while(*p && *p != ']')
 				++p;
-			    if(*p == ']' && !p[1]) UNIPROTO(UNIOPSUB);
+			    if(*p == ']' && !p[1])
+				UNIPROTO(UNIOPSUB,optional);
 			}
 			if (*proto == '&' && *s == '{') {
 			    if (PL_curstash)