diff --git a/tests/bluetooth/tester/overlay-bt_ll_sw_split.conf b/tests/bluetooth/tester/overlay-bt_ll_sw_split.conf
index ac8366b95c0f..ea426a377c59 100644
--- a/tests/bluetooth/tester/overlay-bt_ll_sw_split.conf
+++ b/tests/bluetooth/tester/overlay-bt_ll_sw_split.conf
@@ -32,7 +32,6 @@ CONFIG_BT_CTLR_ISO_TX_SDU_LEN_MAX=310
 
 # CSIP tests requires up to 3 devices
 CONFIG_BT_MAX_CONN=3
-CONFIG_MBEDTLS_PSA_KEY_SLOT_COUNT=3
 
 # BAP/BSRC/SCC/BV-38-C requires 2 BIGs
 CONFIG_BT_EXT_ADV_MAX_ADV_SET=2