diff --git a/src/shared/bus-util.c b/src/shared/bus-util.c
index 90b312a1a76..d9dd3c6a111 100644
--- a/src/shared/bus-util.c
+++ b/src/shared/bus-util.c
@@ -1068,7 +1068,7 @@ static int map_basic(sd_bus *bus, const char *member, sd_bus_message *m, sd_bus_
         }
 
         case SD_BUS_TYPE_UINT32: {
-                uint64_t u;
+                uint32_t u;
                 uint32_t *p = userdata;
 
                 r = sd_bus_message_read_basic(m, type, &u);