diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index dadc24989390..559d7bf30d8f 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -351,7 +351,7 @@ endef
 
 # List module undefined symbols (or empty line if not enabled)
 ifdef CONFIG_TRIM_UNUSED_KSYMS
-cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
+cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | sort -u | xargs echo
 else
 cmd_undef_syms = echo
 endif