diff --git a/R/get-algorithm.R b/R/get-algorithm-logic.R
similarity index 85%
rename from R/get-algorithm.R
rename to R/get-algorithm-logic.R
index 6d96ced..7e2ec98 100644
--- a/R/get-algorithm.R
+++ b/R/get-algorithm-logic.R
@@ -17,5 +17,5 @@ get_algorithm_logic <- function(criteria, algorithm_logic = algorithm) {
     stringr::str_replace_all("AND", "&") |>
     stringr::str_replace_all("OR", "|") |>
     # regex are defined with '=~', so convert them into a stringr function.
-    stringr::str_replace_all("(\\(?)([a-zA-Z0-9_]+)\\)? \\=\\~ ('.*')", "\\1stringr::str_detect(\\2, \\3)")
+    stringr::str_replace_all("([a-zA-Z0-9_]+) \\=\\~ '(.*?)'", "stringr::str_detect(\\1, '\\2')")
 }
diff --git a/tests/testthat/test-get-algorithm-logic.R b/tests/testthat/test-get-algorithm-logic.R
index 159545d..9c93c4b 100644
--- a/tests/testthat/test-get-algorithm-logic.R
+++ b/tests/testthat/test-get-algorithm-logic.R
@@ -1,9 +1,10 @@
 test_algorithm_logic <- data.frame(
-  name = c("hba1c", "podiatrist_services", "gld"),
+  name = c("hba1c", "podiatrist_services", "gld", "some_gld"),
   logic = c(
     "(analysiscode == 'NPU27300' AND value >= 48) OR (analysiscode == 'NPU03835' AND value >= 6.5)",
     "(speciale =~ '^54') AND (barnmak != 0)",
-    "atc =~ '^A10'"
+    "atc =~ '^A10'",
+    "atc =~ '^A10' AND !(atc =~ '^(A10BJ|A10D)')"
   )
 )
 
@@ -21,4 +22,6 @@ test_that("`and` logic and regex within parentheses are converted to R logic", {
   # i.e., the regex is within a parenthesis
   get_algorithm_logic("podiatrist_services", test_algorithm_logic) |>
     expect_equal("(stringr::str_detect(speciale, '^54')) & (barnmak != 0)")
+  get_algorithm_logic("some_gld", test_algorithm_logic) |>
+    expect_equal("stringr::str_detect(atc, '^A10') & !(stringr::str_detect(atc, '^(A10BJ|A10D)'))")
 })