diff --git a/src/network/networkd-route.c b/src/network/networkd-route.c
index e7cc252243..72dbf9ed06 100644
--- a/src/network/networkd-route.c
+++ b/src/network/networkd-route.c
@@ -2814,7 +2814,7 @@ int config_parse_route_mtu(
         }
 
         r = config_parse_mtu(unit, filename, line, section, section_line, lvalue, ltype, rvalue, &n->mtu, userdata);
-        if (r < 0)
+        if (r <= 0)
                 return r;
 
         TAKE_PTR(n);
diff --git a/src/shared/conf-parser.c b/src/shared/conf-parser.c
index 5d4500cb05..1d201528ac 100644
--- a/src/shared/conf-parser.c
+++ b/src/shared/conf-parser.c
@@ -1592,7 +1592,7 @@ int config_parse_mtu(
                 return 0;
         }
 
-        return 0;
+        return 1;
 }
 
 int config_parse_rlimit(