diff --git a/R/backend-dbplyr__duckdb_connection.R b/R/backend-dbplyr__duckdb_connection.R
index a36bf377a..660094e18 100644
--- a/R/backend-dbplyr__duckdb_connection.R
+++ b/R/backend-dbplyr__duckdb_connection.R
@@ -275,10 +275,10 @@ sql_translation.duckdb_connection <- function(con) {
 
       # clock
       add_days = function(x, n, ...) {
-        build_sql("DATE_ADD(", !!x, ", INTERVAL '", n ," day')")
+        build_sql("DATE_ADD(", !!x, ", INTERVAL (", n ,") day)")
       },
       add_years = function(x, n, ...) {
-        build_sql("DATE_ADD(", !!x, ", INTERVAL '", n ," year')")
+        build_sql("DATE_ADD(", !!x, ", INTERVAL (", n ,") year)")
       },
       get_year = function(x) {
         build_sql("DATE_PART('year', ", !!x, ")")
diff --git a/tests/testthat/test-backend-dbplyr__duckdb_connection.R b/tests/testthat/test-backend-dbplyr__duckdb_connection.R
index 0a4435c1e..1d74d44c5 100644
--- a/tests/testthat/test-backend-dbplyr__duckdb_connection.R
+++ b/tests/testthat/test-backend-dbplyr__duckdb_connection.R
@@ -141,11 +141,12 @@ test_that("custom clock functions translated correctly", {
   translate <- function(...) dbplyr::translate_sql(..., con = con)
   sql <- function(...) dbplyr::sql(...)
 
-  expect_equal(translate(add_days(x, 1L)), sql(r"{DATE_ADD(x, INTERVAL '1 day')}"))
-  expect_equal(translate(add_days(x, 2L)), sql(r"{DATE_ADD(x, INTERVAL '2 day')}"))
+  m <- 1
+  expect_equal(translate(add_days(x, m)), sql(r"{DATE_ADD(x, INTERVAL (m) day)}"))
+  expect_equal(translate(add_days(x, 2L)), sql(r"{DATE_ADD(x, INTERVAL (2) day)}"))
 
-  expect_equal(translate(add_years(x, 1L)), sql(r"{DATE_ADD(x, INTERVAL '1 year')}"))
-  expect_equal(translate(add_years(x, 2L)), sql(r"{DATE_ADD(x, INTERVAL '2 year')}"))
+  expect_equal(translate(add_years(x, m)), sql(r"{DATE_ADD(x, INTERVAL (m) year)}"))
+  expect_equal(translate(add_years(x, 2L)), sql(r"{DATE_ADD(x, INTERVAL (2) year)}"))
 
   expect_equal(translate(get_day(x)), sql(r"{DATE_PART('day', x)}"))
   expect_equal(translate(get_month(x)), sql(r"{DATE_PART('month', x)}"))