diff --git a/R/pal-add-remove.R b/R/pal-add-remove.R
index f52393d..9b6ccd6 100644
--- a/R/pal-add-remove.R
+++ b/R/pal-add-remove.R
@@ -46,6 +46,7 @@ pal_add <- function(
 
 #' @rdname pal_add_remove
 pal_remove <- function(role) {
+  check_string(role)
   if (!role %in% list_pals()) {
     cli::cli_abort("No active pal with the given {.arg role}.")
   }
@@ -55,7 +56,6 @@ pal_remove <- function(role) {
     c(paste0("system_prompt_", role), paste0("rs_pal_", role))
   )
 
-
   if (paste0(".last_pal_", role) %in% names(pal_env())) {
     env_unbind(pal_env(), paste0(".last_pal_", role))
   }
@@ -67,7 +67,7 @@ supported_interfaces <- c("replace", "prefix", "suffix")
 
 # given an interface and role, attaches a function binding in pal's
 # additional search env
-parse_interface <- function(interface, role) {
+parse_interface <- function(interface, role, call = caller_env()) {
   if (isTRUE(identical(interface, supported_interfaces))) {
     interface <- interface[1]
   }
@@ -76,13 +76,14 @@ parse_interface <- function(interface, role) {
     !interface %in% supported_interfaces
   )) {
     cli::cli_abort(
-      "{.arg interface} should be one of {.or {.val {supported_interfaces}}}."
+      "{.arg interface} should be one of {.or {.val {supported_interfaces}}}.",
+      call = call
     )
   }
 
   if (interface == "suffix") {
     # TODO: implement suffixing
-    cli::cli_abort("Suffixing not implemented yet.")
+    cli::cli_abort("Suffixing not implemented yet.", call = call)
   }
 
   .stash_binding(
diff --git a/tests/testthat/_snaps/pal-add-remove.md b/tests/testthat/_snaps/pal-add-remove.md
index e2da737..34356c3 100644
--- a/tests/testthat/_snaps/pal-add-remove.md
+++ b/tests/testthat/_snaps/pal-add-remove.md
@@ -6,3 +6,51 @@
       
       -- A boopery pal using claude-3-5-sonnet-20240620. 
 
+# pal addition with bad inputs
+
+    Code
+      pal_add(role = identity, prompt = "hey")
+    Condition
+      Error in `pal_add()`:
+      ! `role` must be a single string, not a function.
+
+---
+
+    Code
+      pal_add(role = "sillyhead", prompt = "hey", interface = "no")
+    Condition
+      Error in `pal_add()`:
+      ! `interface` should be one of "replace", "prefix", or "suffix".
+
+---
+
+    Code
+      pal_add(role = "sillyhead", prompt = "hey", interface = "suffix")
+    Condition
+      Error in `pal_add()`:
+      ! Suffixing not implemented yet.
+
+---
+
+    Code
+      pal_add(role = "sillyhead", prompt = "hey", interface = NULL)
+    Condition
+      Error in `pal_add()`:
+      ! `interface` should be one of "replace", "prefix", or "suffix".
+
+# pal remove with bad inputs
+
+    Code
+      pal_remove(role = identity)
+    Condition
+      Error in `pal_remove()`:
+      ! `role` must be a single string, not a function.
+
+---
+
+    Code
+      pal_remove(role = "notAnActivePal")
+    Condition
+      Error in `pal_remove()`:
+      ! No active pal with the given `role`.
+
diff --git a/tests/testthat/test-pal-add-remove.R b/tests/testthat/test-pal-add-remove.R
index fa52d79..e9c3d01 100644
--- a/tests/testthat/test-pal-add-remove.R
+++ b/tests/testthat/test-pal-add-remove.R
@@ -24,3 +24,37 @@ test_that("pal addition and removal works", {
   expect_false("system_prompt_boopery" %in% names(pal_env()))
   expect_false("rs_pal_boopery" %in% names(pal_env()))
 })
+
+test_that("pal addition with bad inputs", {
+  expect_snapshot(
+    error = TRUE,
+    pal_add(role = identity, prompt = "hey")
+  )
+
+  # TODO: decide on `prompt` interface and test
+
+
+  expect_snapshot(
+    error = TRUE,
+    pal_add(role = "sillyhead", prompt = "hey", interface = "no")
+  )
+  expect_snapshot(
+    error = TRUE,
+    pal_add(role = "sillyhead", prompt = "hey", interface = "suffix")
+  )
+  expect_snapshot(
+    error = TRUE,
+    pal_add(role = "sillyhead", prompt = "hey", interface = NULL)
+  )
+})
+
+test_that("pal remove with bad inputs", {
+  expect_snapshot(
+    error = TRUE,
+    pal_remove(role = identity)
+  )
+  expect_snapshot(
+    error = TRUE,
+    pal_remove(role = "notAnActivePal")
+  )
+})