diff --git a/CHANGELOG b/CHANGELOG
index 3fe3e77..792ef3d 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -41,8 +41,11 @@ version 2.80
 	Fix missing fatal errors with some malformed options
 	(server, local, address, rebind-domain-ok, ipset, alias).
 	Thanks to Eugene Lozovoy for spotting the problem.
-	
-	
+
+	Fix crash on startup with a --synth-domain which has no prefix.
+	Introduced in 2.79. Thanks to Andreas Engel for the bug report.
+
+
 version 2.79
 	Fix parsing of CNAME arguments, which are confused by extra spaces.
 	Thanks to Diego Aguirre for spotting the bug.
diff --git a/src/option.c b/src/option.c
index 9f1b84f..c203826 100644
--- a/src/option.c
+++ b/src/option.c
@@ -2232,7 +2232,9 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 		      char *star;
 		      new->next = daemon->synth_domains;
 		      daemon->synth_domains = new;
-		      if ((star = strrchr(new->prefix, '*')) && *(star+1) == 0)
+		      if (new->prefix &&
+			  (star = strrchr(new->prefix, '*'))
+			  && *(star+1) == 0)
 			{
 			  *star = 0;
 			  new->indexed = 1;