diff --git a/src/client/commands/edit_privs.rs b/src/client/commands/edit_privs.rs
index ee689aa..400ff93 100644
--- a/src/client/commands/edit_privs.rs
+++ b/src/client/commands/edit_privs.rs
@@ -305,7 +305,7 @@ pub async fn edit_database_privileges(
 
     print_modify_database_privileges_output_status(&result);
 
-    if result.iter().any(|(_, res)| {
+    if result.values().flatten().any(|(_, res)| {
         matches!(
             res,
             Err(ModifyDatabasePrivilegesError::UserValidationError(
@@ -320,7 +320,7 @@ pub async fn edit_database_privileges(
 
     server_connection.send(Request::Exit).await?;
 
-    if result.values().any(std::result::Result::is_err) {
+    if result.values().flatten().any(|(_, res)| res.is_err()) {
         std::process::exit(1);
     }
 
diff --git a/src/core/protocol/commands.rs b/src/core/protocol/commands.rs
index 35ff9a1..b76da3f 100644
--- a/src/core/protocol/commands.rs
+++ b/src/core/protocol/commands.rs
@@ -324,9 +324,12 @@ impl Response {
                 ResponseOkStatus::from_counts(res.len(), res.values().filter(|v| v.is_ok()).count())
             }
             Response::ListAllPrivileges(res) => ResponseOkStatus::from_bool(res.is_ok()),
-            Response::ModifyPrivileges(res) => {
-                ResponseOkStatus::from_counts(res.len(), res.values().filter(|v| v.is_ok()).count())
-            }
+            Response::ModifyPrivileges(res) => ResponseOkStatus::from_counts(
+                res.len(),
+                res.values()
+                    .map(|user_map| user_map.values().filter(|v| v.is_ok()).count())
+                    .sum(),
+            ),
 
             Response::CreateUsers(res) => {
                 ResponseOkStatus::from_counts(res.len(), res.values().filter(|v| v.is_ok()).count())
diff --git a/src/core/protocol/commands/modify_privileges.rs b/src/core/protocol/commands/modify_privileges.rs
index 35fbd11..4e7f3f1 100644
--- a/src/core/protocol/commands/modify_privileges.rs
+++ b/src/core/protocol/commands/modify_privileges.rs
@@ -12,7 +12,7 @@ use crate::core::{
 pub type ModifyPrivilegesRequest = BTreeSet<DatabasePrivilegesDiff>;
 
 pub type ModifyPrivilegesResponse =
-    BTreeMap<(MySQLDatabase, MySQLUser), Result<(), ModifyDatabasePrivilegesError>>;
+    BTreeMap<MySQLDatabase, BTreeMap<MySQLUser, Result<(), ModifyDatabasePrivilegesError>>>;
 
 #[derive(Error, Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub enum ModifyDatabasePrivilegesError {
@@ -49,7 +49,11 @@ pub enum DiffDoesNotApplyError {
 }
 
 pub fn print_modify_database_privileges_output_status(output: &ModifyPrivilegesResponse) {
-    for ((database_name, username), result) in output {
+    for ((database_name, username), result) in output.iter().flat_map(|(db, user_map)| {
+        user_map
+            .iter()
+            .map(move |(user, result)| ((db, user), result))
+    }) {
         match result {
             Ok(()) => {
                 println!(
@@ -169,13 +173,16 @@ mod tests {
 
     #[test]
     fn test_serialize_deserialize_response() {
-        let response: ModifyPrivilegesResponse = BTreeMap::from([
-            (("test_db".into(), "test_user".into()), Ok(())),
-            (
-                ("test_db".into(), "invalid_user".into()),
-                Err(ModifyDatabasePrivilegesError::UserDoesNotExist),
-            ),
-        ]);
+        let response: ModifyPrivilegesResponse = BTreeMap::from([(
+            "test_db".into(),
+            BTreeMap::from([
+                ("test_user".into(), Ok(())),
+                (
+                    "invalid_user".into(),
+                    Err(ModifyDatabasePrivilegesError::UserDoesNotExist),
+                ),
+            ]),
+        )]);
 
         let json = serde_json::to_string_pretty(&response).unwrap();
         println!("Serialized response:\n{}", json);
diff --git a/src/server/sql/database_privilege_operations.rs b/src/server/sql/database_privilege_operations.rs
index 0c4c8b7..7fb41f5 100644
--- a/src/server/sql/database_privilege_operations.rs
+++ b/src/server/sql/database_privilege_operations.rs
@@ -488,4 +488,13 @@ pub async fn apply_privilege_diffs(
     }
 
     results
+        .into_iter()
+        .map(|((k1, k2), v)| (k1, (k2, v)))
+        .into_group_map()
+        .into_iter()
+        .map(|(k1, pairs)| {
+            let inner = pairs.into_iter().collect::<BTreeMap<_, _>>();
+            (k1, inner)
+        })
+        .collect()
 }