diff --git a/meson.build b/meson.build
index 9f0a0f97f1..11b73bcb19 100644
--- a/meson.build
+++ b/meson.build
@@ -2275,6 +2275,7 @@ public_programs += [exe]
 
 exe = executable('udevadm',
                  udevadm_sources,
+                 c_args : ['-DLOG_REALM=LOG_REALM_UDEV'],
                  include_directories : includes,
                  link_with : [libudev_core,
                               libsystemd_network,
diff --git a/src/udev/meson.build b/src/udev/meson.build
index d01cf8f194..3b2c7b5e12 100644
--- a/src/udev/meson.build
+++ b/src/udev/meson.build
@@ -130,6 +130,7 @@ libudev_core = static_library(
         link_config_gperf_c,
         keyboard_keys_from_name_h,
         include_directories : libudev_core_includes,
+        c_args : ['-DLOG_REALM=LOG_REALM_UDEV'],
         link_with : udev_link_with,
         dependencies : [libblkid, libkmod])