diff --git a/src/libsystemd/sd-bus/bus-match.c b/src/libsystemd/sd-bus/bus-match.c
index 6812c28904a..ad135406f68 100644
--- a/src/libsystemd/sd-bus/bus-match.c
+++ b/src/libsystemd/sd-bus/bus-match.c
@@ -864,7 +864,7 @@ char *bus_match_to_string(struct bus_match_component *components, unsigned n_com
         if (!f)
                 return NULL;
 
-        __fsetlocking(f, FSETLOCKING_BYCALLER);
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 
         for (i = 0; i < n_components; i++) {
                 char buf[32];
diff --git a/src/resolve/resolved-dns-dnssec.c b/src/resolve/resolved-dns-dnssec.c
index d9633629e85..335fd477800 100644
--- a/src/resolve/resolved-dns-dnssec.c
+++ b/src/resolve/resolved-dns-dnssec.c
@@ -804,7 +804,7 @@ int dnssec_verify_rrset(
         f = open_memstream(&sig_data, &sig_size);
         if (!f)
                 return -ENOMEM;
-        __fsetlocking(f, FSETLOCKING_BYCALLER);
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 
         fwrite_uint16(f, rrsig->rrsig.type_covered);
         fwrite_uint8(f, rrsig->rrsig.algorithm);