diff --git a/R/telemetry.R b/R/telemetry.R
index 41c2eb9e..2937ba6f 100644
--- a/R/telemetry.R
+++ b/R/telemetry.R
@@ -231,8 +231,12 @@ expr_to_json <- function(x, name_map) {
 
 expr_scrub <- function(x, name_map) {
   do_scrub <- function(xx, callee = FALSE) {
-    if (is.null(xx)) {
-      return(NULL)
+    if (is.character(xx))  {
+      return("<character>")
+    } else if (is.factor(xx)) {
+      return("<factor>")
+    } else if (is.atomic(xx)) {
+      return(xx)
     } else if (is_symbol(xx)) {
       if (callee) {
         return(xx)
diff --git a/tests/testthat/_snaps/fallback.md b/tests/testthat/_snaps/fallback.md
index 0b355ebc..b432bfe3 100644
--- a/tests/testthat/_snaps/fallback.md
+++ b/tests/testthat/_snaps/fallback.md
@@ -81,7 +81,7 @@
         a, label = TRUE))
     Message
       i dplyr fallback recorded
-        {"version":"0.3.1","message":"wday(label = ) not supported","name":"mutate","x":{"...1":"Date"},"args":{"dots":{"...2":"...3::...4(...1, label = \"Don't know how to scrub logical\")"},".by":"NULL",".keep":["all","used","unused","none"]}}
+        {"version":"0.3.1","message":"wday(label = ) not supported","name":"mutate","x":{"...1":"Date"},"args":{"dots":{"...2":"...3::...4(...1, label = TRUE)"},".by":"NULL",".keep":["all","used","unused","none"]}}
     Output
       # A tibble: 1 x 2
         a          b    
@@ -109,7 +109,7 @@
         a, format = "%Y-%m-%d", tz = "CET"))
     Message
       i dplyr fallback recorded
-        {"version":"0.3.1","message":"strftime(tz = ) not supported","name":"mutate","x":{"...1":"Date"},"args":{"dots":{"...2":"strftime(...1, format = \"Don't know how to scrub character\", tz = \"Don't know how to scrub character\")"},".by":"NULL",".keep":["all","used","unused","none"]}}
+        {"version":"0.3.1","message":"strftime(tz = ) not supported","name":"mutate","x":{"...1":"Date"},"args":{"dots":{"...2":"strftime(...1, format = \"<character>\", tz = \"<character>\")"},".by":"NULL",".keep":["all","used","unused","none"]}}
     Output
       # A tibble: 1 x 2
         a          b         
diff --git a/tests/testthat/_snaps/telemetry.md b/tests/testthat/_snaps/telemetry.md
index a3aafb09..92560bef 100644
--- a/tests/testthat/_snaps/telemetry.md
+++ b/tests/testthat/_snaps/telemetry.md
@@ -56,7 +56,7 @@
       tibble(a = 1:3, b = 4:6) %>% as_duckplyr_df() %>% filter(a > 1, .by = b)
     Condition
       Error in `rel_try()`:
-      ! filter: {"version":"0.3.1","message":"Error in filter","name":"filter","x":{"...1":"integer","...2":"integer"},"args":{"dots":{"1":"...1 > \"Don't know how to scrub numeric\""},"by":"...2","preserve":false}}
+      ! filter: {"version":"0.3.1","message":"Error in filter","name":"filter","x":{"...1":"integer","...2":"integer"},"args":{"dots":{"1":"...1 > 1"},"by":"...2","preserve":false}}
 
 ---
 
@@ -64,7 +64,7 @@
       tibble(a = 1:3, b = 4:6) %>% as_duckplyr_df() %>% filter(a > 1, .preserve = TRUE)
     Condition
       Error in `rel_try()`:
-      ! filter: {"version":"0.3.1","message":"Error in filter","name":"filter","x":{"...1":"integer","...2":"integer"},"args":{"dots":{"1":"...1 > \"Don't know how to scrub numeric\""},"by":"NULL","preserve":true}}
+      ! filter: {"version":"0.3.1","message":"Error in filter","name":"filter","x":{"...1":"integer","...2":"integer"},"args":{"dots":{"1":"...1 > 1"},"by":"NULL","preserve":true}}
 
 # telemetry and full_join()