diff --git a/CHANGELOG b/CHANGELOG
index b7aa3ca..31be3ed 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -79,6 +79,7 @@ xx/xx/2018 autofs-5.1.5
 - fix a regression with map instance lookup.
 - fix trailing dollar sun entry expansion.
 - initialize struct addrinfo for getaddrinfo() calls.
+- fix quoted string length calc in expandsunent().
 
 19/12/2017 autofs-5.1.4
 - fix spec file url.
diff --git a/modules/parse_sun.c b/modules/parse_sun.c
index bfb4c84..31c55af 100644
--- a/modules/parse_sun.c
+++ b/modules/parse_sun.c
@@ -213,9 +213,11 @@ int expandsunent(const char *src, char *dst, const char *key,
 					*dst++ = *src;
 				src++;
 			}
-			if (*src && dst) {
+			if (*src) {
 				len++;
-				*dst++ = *src++;
+				if (dst)
+					*dst++ = *src;
+				src++;
 			}
 			break;