diff --git a/tests/unit/Makefile.am b/tests/unit/Makefile.am
index c503e5d41..25f4b2673 100644
--- a/tests/unit/Makefile.am
+++ b/tests/unit/Makefile.am
@@ -51,7 +51,6 @@ if OPENTHREAD_BUILD_TESTS
 
 AM_CPPFLAGS                                                         = \
     -DOPENTHREAD_FTD=1                                                \
-    -DOPENTHREAD_CONFIG_LOG_PLATFORM=0                                \
     -I$(top_srcdir)/include                                           \
     -I$(top_srcdir)/src                                               \
     -I$(top_srcdir)/src/core                                          \