diff --git a/meson.build b/meson.build
index 5706c776ff..504644bca8 100644
--- a/meson.build
+++ b/meson.build
@@ -510,6 +510,10 @@ conf.set('SIZEOF_TIME_T', cc.sizeof('time_t', prefix : '#include <sys/time.h>'))
 conf.set('SIZEOF_RLIM_T', cc.sizeof('rlim_t', prefix : '#include <sys/resource.h>'))
 conf.set('SIZEOF_TIMEX_MEMBER', cc.sizeof('typeof(((struct timex *)0)->freq)', prefix : '#include <sys/timex.h>'))
 
+long_max = cc.compute_int('LONG_MAX', prefix : '#include <limits.h>')
+assert(long_max > 100000)
+conf.set_quoted('LONG_MAX_STR', '@0@'.format(long_max))
+
 decl_headers = '''
 #include <uchar.h>
 #include <sys/mount.h>
diff --git a/src/basic/constants.h b/src/basic/constants.h
index 54021911ab..4a24ba9c8c 100644
--- a/src/basic/constants.h
+++ b/src/basic/constants.h
@@ -43,7 +43,7 @@
 #define DEFAULT_EXIT_USEC (30*USEC_PER_SEC)
 
 /* The default value for the net.unix.max_dgram_qlen sysctl */
-#define DEFAULT_UNIX_MAX_DGRAM_QLEN 512UL
+#define DEFAULT_UNIX_MAX_DGRAM_QLEN 512
 
 #define SIGNALS_CRASH_HANDLER SIGSEGV,SIGILL,SIGFPE,SIGBUS,SIGQUIT,SIGABRT
 #define SIGNALS_IGNORE SIGPIPE
diff --git a/src/core/main.c b/src/core/main.c
index 119c518664..9c1de3624c 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -1184,9 +1184,10 @@ static void bump_file_max_and_nr_open(void) {
 #if BUMP_PROC_SYS_FS_FILE_MAX
         /* The maximum the kernel allows for this since 5.2 is LONG_MAX, use that. (Previously things were
          * different, but the operation would fail silently.) */
-        r = sysctl_writef("fs/file-max", "%li\n", LONG_MAX);
+        r = sysctl_write("fs/file-max", LONG_MAX_STR);
         if (r < 0)
-                log_full_errno(IN_SET(r, -EROFS, -EPERM, -EACCES) ? LOG_DEBUG : LOG_WARNING, r, "Failed to bump fs.file-max, ignoring: %m");
+                log_full_errno(IN_SET(r, -EROFS, -EPERM, -EACCES) ? LOG_DEBUG : LOG_WARNING,
+                               r, "Failed to bump fs.file-max, ignoring: %m");
 #endif
 
 #if BUMP_PROC_SYS_FS_NR_OPEN
@@ -1218,7 +1219,7 @@ static void bump_file_max_and_nr_open(void) {
                         break;
                 }
 
-                r = sysctl_writef("fs/nr_open", "%i\n", v);
+                r = sysctl_writef("fs/nr_open", "%i", v);
                 if (r == -EINVAL) {
                         log_debug("Couldn't write fs.nr_open as %i, halving it.", v);
                         v /= 2;
@@ -1404,8 +1405,7 @@ static int bump_unix_max_dgram_qlen(void) {
         if (v >= DEFAULT_UNIX_MAX_DGRAM_QLEN)
                 return 0;
 
-        r = write_string_filef("/proc/sys/net/unix/max_dgram_qlen", WRITE_STRING_FILE_DISABLE_BUFFER,
-                               "%lu", DEFAULT_UNIX_MAX_DGRAM_QLEN);
+        r = sysctl_write("net/unix/max_dgram_qlen", STRINGIFY(DEFAULT_UNIX_MAX_DGRAM_QLEN));
         if (r < 0)
                 return log_full_errno(IN_SET(r, -EROFS, -EPERM, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
                                       "Failed to bump AF_UNIX datagram queue length, ignoring: %m");