diff --git a/src/journal/fuzz-journald-stream.c b/src/journal/fuzz-journald-stream.c
index eb1feda662..51c79ece64 100644
--- a/src/journal/fuzz-journald-stream.c
+++ b/src/journal/fuzz-journald-stream.c
@@ -10,27 +10,27 @@
 #include "fuzz.h"
 #include "fuzz-journald-util.h"
 #include "journald-stream.h"
+#include "tests.h"
 
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-        _cleanup_close_pair_ int stream_fds[2] = EBADF_PAIR;
-        _cleanup_(manager_freep) Manager *m = NULL;
-        StdoutStream *stream;
-        int v, fd0;
-
         if (outside_size_range(size, 1, 65536))
                 return 0;
 
         fuzz_setup_logging();
 
-        assert_se(socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0, stream_fds) >= 0);
-        dummy_manager_new(&m, NULL, 0);
+        _cleanup_close_pair_ int stream_fds[2] = EBADF_PAIR;
+        ASSERT_OK_ERRNO(socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0, stream_fds));
 
-        assert_se(stdout_stream_install(m, stream_fds[0], &stream) >= 0);
-        fd0 = TAKE_FD(stream_fds[0]); /* avoid double close */
+        _cleanup_(manager_freep) Manager *m = NULL;
+        dummy_manager_new(&m, /* buffer= */ NULL, /* size= */ 0);
 
-        assert_se(write(stream_fds[1], data, size) == (ssize_t) size);
-        while (ioctl(fd0, SIOCINQ, &v) == 0 && v)
-                sd_event_run(m->event, UINT64_MAX);
+        StdoutStream *stream;
+        ASSERT_OK(stdout_stream_install(m, stream_fds[0], &stream));
+        int fd0 = TAKE_FD(stream_fds[0]); /* avoid double close */
+
+        ASSERT_OK_EQ_ERRNO(write(stream_fds[1], data, size), (ssize_t) size);
+        for (int v; ioctl(fd0, SIOCINQ, &v) == 0 && v > 0;)
+                ASSERT_OK(sd_event_run(m->event, UINT64_MAX));
 
         if (m->n_stdout_streams > 0)
                 stdout_stream_terminate(stream);