diff --git a/tests/nimble_rpble_gnrc/Makefile b/tests/nimble_rpble_gnrc/Makefile
index bb23b35c4c..b57fffb558 100644
--- a/tests/nimble_rpble_gnrc/Makefile
+++ b/tests/nimble_rpble_gnrc/Makefile
@@ -17,7 +17,7 @@ USEMODULE += auto_init_gnrc_rpl
 # configure and use Nimble
 USEMODULE += bluetil_addr
 USEMODULE += nimble_rpble
-NIMBLE_MAX_CONN := 3
+NIMBLE_MAX_CONN = 3
 
 DEVELHELP = 0