diff --git a/R/custom_antimicrobials.R b/R/custom_antimicrobials.R
index b7324dcdd..78a4f8afa 100755
--- a/R/custom_antimicrobials.R
+++ b/R/custom_antimicrobials.R
@@ -165,7 +165,7 @@ add_custom_antimicrobials <- function(x) {
 #' @export
 clear_custom_antimicrobials <- function() {
   n <- nrow(AMR_env$AB_lookup)
-  AMR_env$AB_lookup <- create_AB_lookup()
+  AMR_env$AB_lookup <- cbind(AMR::antibiotics, AB_LOOKUP)
   n2 <- nrow(AMR_env$AB_lookup)
   AMR_env$custom_ab_codes <- character(0)
   AMR_env$ab_previously_coerced <- AMR_env$ab_previously_coerced[which(AMR_env$ab_previously_coerced$ab %in% AMR_env$AB_lookup$ab), , drop = FALSE]