diff --git a/NEWS.md b/NEWS.md
index 78ff3aa75..9860353d9 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -15,6 +15,8 @@
   
 * `across(everything())` doesn't select grouping columns created via `.by` in
   `summarise()` (@mgirlich, #1493).
+*  Use `COUNT_BIG` instead of `COUNT` for SQL server so that `tally()` and
+  `count()` work regardless of size of the data (@edward-burn, #1498).
 
 *  New translations of clock function `date_count_between()` for SQL server, Redshift, Snowflake, Postgres, and Spark (@edward-burn, #1495).
 
diff --git a/R/backend-mssql.R b/R/backend-mssql.R
index ac65bc08e..0bb3b9d9d 100644
--- a/R/backend-mssql.R
+++ b/R/backend-mssql.R
@@ -425,6 +425,7 @@ simulate_mssql <- function(version = "15.0") {
   sql_variant(
     mssql_scalar,
     sql_translator(.parent = base_odbc_agg,
+      n           = function() sql("COUNT_BIG(*)"),
       sd            = sql_aggregate("STDEV", "sd"),
       var           = sql_aggregate("VAR", "var"),
       str_flatten = function(x, collapse = "") sql_expr(string_agg(!!x, !!collapse)),
diff --git a/tests/testthat/_snaps/backend-mssql.md b/tests/testthat/_snaps/backend-mssql.md
index 3ad0ef302..4f9918900 100644
--- a/tests/testthat/_snaps/backend-mssql.md
+++ b/tests/testthat/_snaps/backend-mssql.md
@@ -497,6 +497,38 @@
       FROM `df`
       ORDER BY `y`
 
+# count_big
+
+    Code
+      dplyr::count(mf)
+    Output
+      <SQL>
+      SELECT COUNT_BIG(*) AS `n`
+      FROM `df`
+
+---
+
+    Code
+      dplyr::tally(mf)
+    Output
+      <SQL>
+      SELECT COUNT_BIG(*) AS `n`
+      FROM `df`
+
+# can copy_to() and compute() with temporary tables (#438)
+
+    Code
+      db <- copy_to(con, df, name = unique_table_name(), temporary = TRUE)
+    Message
+      Created a temporary table named #dbplyr_{tmp}
+
+---
+
+    Code
+      db2 <- db %>% mutate(y = x + 1) %>% compute()
+    Message
+      Created a temporary table named #dbplyr_{tmp}
+
 # add prefix to temporary table
 
     Code