diff --git a/R/data_extract_module.R b/R/data_extract_module.R
index 09285786..1ff4e149 100644
--- a/R/data_extract_module.R
+++ b/R/data_extract_module.R
@@ -457,7 +457,7 @@ data_extract_srv.list <- function(id, datasets, data_extract_spec, join_keys = N
 
       # get keys out of join_keys
       if (!is.null(join_keys)) {
-        keys <- sapply(names(datasets), simplify = FALSE, function(x) join_keys[x, x])
+        keys <- sapply(names(datasets), simplify = FALSE, function(x) join_keys[[x]][[x]])
       } else {
         keys <- sapply(names(datasets), simplify = FALSE, function(x) character(0))
       }
diff --git a/R/get_merge_call.R b/R/get_merge_call.R
index 1b22ed1d..4541b369 100644
--- a/R/get_merge_call.R
+++ b/R/get_merge_call.R
@@ -130,7 +130,7 @@ get_merge_key_grid <- function(selector_list, join_keys = teal.data::join_keys()
           get_merge_key_pair(
             selector_from,
             selector_to,
-            join_keys[selector_from$dataname, selector_to$dataname]
+            join_keys[[selector_from$dataname]][[selector_to$dataname]]
           )
         }
       )
diff --git a/R/merge_datasets.R b/R/merge_datasets.R
index 3ff60973..87fd3b76 100644
--- a/R/merge_datasets.R
+++ b/R/merge_datasets.R
@@ -278,7 +278,7 @@ are_needed_keys_provided <- function(join_keys, merged_selector_list) {
   }
 
   do_join_keys_exist <- function(dataset_name1, dataset_name2, join_keys) {
-    length(join_keys[dataset_name1, dataset_name2] > 0)
+    length(join_keys[[dataset_name1]][[dataset_name2]] > 0)
   }
 
   datasets_names <- vapply(merged_selector_list, function(slice) slice[["dataname"]], FUN.VALUE = character(1))
diff --git a/tests/testthat/test-merge_expression_srv.R b/tests/testthat/test-merge_expression_srv.R
index 13212421..bc6b43f8 100644
--- a/tests/testthat/test-merge_expression_srv.R
+++ b/tests/testthat/test-merge_expression_srv.R
@@ -20,7 +20,7 @@ adsl_data_extract_srv_output <-
     dataname = "ADSL",
     filters = NULL,
     select = "AGE",
-    keys = join_keys["ADSL", "ADSL"],
+    keys = join_keys[["ADSL", "ADSL"]],
     reshape = FALSE,
     internal_id = "adsl_extract"
   )
@@ -30,7 +30,7 @@ adlb_data_extract_srv_output <-
     dataname = "ADLB",
     filters = NULL,
     select = c("AVAL", "CHG"),
-    keys = join_keys["ADLB", "ADLB"],
+    keys = join_keys[["ADLB", "ADLB"]],
     reshape = FALSE,
     internal_id = "adlb_extract"
   )