diff --git a/examples/compiler/class_table.rs b/examples/compiler/class_table.rs
index db21980a..0e009a28 100644
--- a/examples/compiler/class_table.rs
+++ b/examples/compiler/class_table.rs
@@ -9,12 +9,12 @@ salsa::query_group! {
         }
 
         /// Get the list of all classes
-        fn all_classes(key: ()) -> Arc<Vec<DefId>> {
+        fn all_classes() -> Arc<Vec<DefId>> {
             type AllClasses;
         }
 
         /// Get the list of all fields
-        fn all_fields(key: ()) -> Arc<Vec<DefId>> {
+        fn all_fields() -> Arc<Vec<DefId>> {
             type AllFields;
         }
     }
@@ -23,7 +23,7 @@ salsa::query_group! {
 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
 pub struct DefId(usize);
 
-fn all_classes(_: &impl ClassTableDatabase, (): ()) -> Arc<Vec<DefId>> {
+fn all_classes(_: &impl ClassTableDatabase) -> Arc<Vec<DefId>> {
     Arc::new(vec![DefId(0), DefId(10)]) // dummy impl
 }
 
@@ -31,14 +31,15 @@ fn fields(_: &impl ClassTableDatabase, class: DefId) -> Arc<Vec<DefId>> {
     Arc::new(vec![DefId(class.0 + 1), DefId(class.0 + 2)]) // dummy impl
 }
 
-fn all_fields(db: &impl ClassTableDatabase, (): ()) -> Arc<Vec<DefId>> {
+fn all_fields(db: &impl ClassTableDatabase) -> Arc<Vec<DefId>> {
     Arc::new(
-        db.all_classes(())
+        db.all_classes()
             .iter()
             .cloned()
             .flat_map(|def_id| {
                 let fields = db.fields(def_id);
                 (0..fields.len()).map(move |i| fields[i])
-            }).collect(),
+            })
+            .collect(),
     )
 }
diff --git a/examples/compiler/main.rs b/examples/compiler/main.rs
index 85d9c5fc..5f0cee0f 100644
--- a/examples/compiler/main.rs
+++ b/examples/compiler/main.rs
@@ -8,7 +8,7 @@ use self::implementation::DatabaseImpl;
 #[test]
 fn test() {
     let query = DatabaseImpl::default();
-    let all_def_ids = query.all_fields(());
+    let all_def_ids = query.all_fields();
     assert_eq!(
         format!("{:?}", all_def_ids),
         "[DefId(1), DefId(2), DefId(11), DefId(12)]"
@@ -17,7 +17,7 @@ fn test() {
 
 fn main() {
     let query = DatabaseImpl::default();
-    for f in query.all_fields(()).iter() {
+    for f in query.all_fields().iter() {
         println!("{:?}", f);
     }
 }
diff --git a/tests/cycles.rs b/tests/cycles.rs
index 4bc27c36..39e887aa 100644
--- a/tests/cycles.rs
+++ b/tests/cycles.rs
@@ -23,49 +23,49 @@ salsa::database_storage! {
 salsa::query_group! {
     trait Database: salsa::Database {
         // `a` and `b` depend on each other and form a cycle
-        fn memoized_a(key: ()) -> () {
+        fn memoized_a() -> () {
             type MemoizedA;
         }
-        fn memoized_b(key: ()) -> () {
+        fn memoized_b() -> () {
             type MemoizedB;
         }
-        fn volatile_a(key: ()) -> () {
+        fn volatile_a() -> () {
             type VolatileA;
             storage volatile;
         }
-        fn volatile_b(key: ()) -> () {
+        fn volatile_b() -> () {
             type VolatileB;
             storage volatile;
         }
     }
 }
 
-fn memoized_a(db: &impl Database, (): ()) -> () {
-    db.memoized_b(())
+fn memoized_a(db: &impl Database) -> () {
+    db.memoized_b()
 }
 
-fn memoized_b(db: &impl Database, (): ()) -> () {
-    db.memoized_a(())
+fn memoized_b(db: &impl Database) -> () {
+    db.memoized_a()
 }
 
-fn volatile_a(db: &impl Database, (): ()) -> () {
-    db.volatile_b(())
+fn volatile_a(db: &impl Database) -> () {
+    db.volatile_b()
 }
 
-fn volatile_b(db: &impl Database, (): ()) -> () {
-    db.volatile_a(())
+fn volatile_b(db: &impl Database) -> () {
+    db.volatile_a()
 }
 
 #[test]
 #[should_panic(expected = "cycle detected")]
 fn cycle_memoized() {
     let query = DatabaseImpl::default();
-    query.memoized_a(());
+    query.memoized_a();
 }
 
 #[test]
 #[should_panic(expected = "cycle detected")]
 fn cycle_volatile() {
     let query = DatabaseImpl::default();
-    query.volatile_a(());
+    query.volatile_a();
 }
diff --git a/tests/incremental/memoized_dep_inputs.rs b/tests/incremental/memoized_dep_inputs.rs
index 152ceb61..66692784 100644
--- a/tests/incremental/memoized_dep_inputs.rs
+++ b/tests/incremental/memoized_dep_inputs.rs
@@ -3,40 +3,40 @@ use salsa::Database;
 
 salsa::query_group! {
     pub(crate) trait MemoizedDepInputsContext: TestContext {
-        fn dep_memoized2(key: ()) -> usize {
+        fn dep_memoized2() -> usize {
             type Memoized2;
         }
-        fn dep_memoized1(key: ()) -> usize {
+        fn dep_memoized1() -> usize {
             type Memoized1;
         }
-        fn dep_derived1(key: ()) -> usize {
+        fn dep_derived1() -> usize {
             type Derived1;
             storage dependencies;
         }
-        fn dep_input1(key: ()) -> usize {
+        fn dep_input1() -> usize {
             type Input1;
             storage input;
         }
-        fn dep_input2(key: ()) -> usize {
+        fn dep_input2() -> usize {
             type Input2;
             storage input;
         }
     }
 }
 
-fn dep_memoized2(db: &impl MemoizedDepInputsContext, (): ()) -> usize {
+fn dep_memoized2(db: &impl MemoizedDepInputsContext) -> usize {
     db.log().add("Memoized2 invoked");
-    db.dep_memoized1(())
+    db.dep_memoized1()
 }
 
-fn dep_memoized1(db: &impl MemoizedDepInputsContext, (): ()) -> usize {
+fn dep_memoized1(db: &impl MemoizedDepInputsContext) -> usize {
     db.log().add("Memoized1 invoked");
-    db.dep_derived1(()) * 2
+    db.dep_derived1() * 2
 }
 
-fn dep_derived1(db: &impl MemoizedDepInputsContext, (): ()) -> usize {
+fn dep_derived1(db: &impl MemoizedDepInputsContext) -> usize {
     db.log().add("Derived1 invoked");
-    db.dep_input1(()) / 2
+    db.dep_input1() / 2
 }
 
 #[test]
@@ -44,7 +44,7 @@ fn revalidate() {
     let db = &TestContextImpl::default();
 
     // Initial run starts from Memoized2:
-    let v = db.dep_memoized2(());
+    let v = db.dep_memoized2();
     assert_eq!(v, 0);
     db.assert_log(&["Memoized2 invoked", "Memoized1 invoked", "Derived1 invoked"]);
 
@@ -52,19 +52,19 @@ fn revalidate() {
     // running Memoized2. Note that we don't try to validate
     // Derived1, so it is invoked by Memoized1.
     db.query(Input1).set((), 44);
-    let v = db.dep_memoized2(());
+    let v = db.dep_memoized2();
     assert_eq!(v, 44);
     db.assert_log(&["Memoized1 invoked", "Derived1 invoked", "Memoized2 invoked"]);
 
     // Here validation of Memoized1 succeeds so Memoized2 never runs.
     db.query(Input1).set((), 45);
-    let v = db.dep_memoized2(());
+    let v = db.dep_memoized2();
     assert_eq!(v, 44);
     db.assert_log(&["Memoized1 invoked", "Derived1 invoked"]);
 
     // Here, a change to input2 doesn't affect us, so nothing runs.
     db.query(Input2).set((), 45);
-    let v = db.dep_memoized2(());
+    let v = db.dep_memoized2();
     assert_eq!(v, 44);
     db.assert_log(&[]);
 }
diff --git a/tests/incremental/memoized_inputs.rs b/tests/incremental/memoized_inputs.rs
index 23e690f3..d518d711 100644
--- a/tests/incremental/memoized_inputs.rs
+++ b/tests/incremental/memoized_inputs.rs
@@ -3,45 +3,45 @@ use salsa::Database;
 
 salsa::query_group! {
     pub(crate) trait MemoizedInputsContext: TestContext {
-        fn max(key: ()) -> usize {
+        fn max() -> usize {
             type Max;
         }
-        fn input1(key: ()) -> usize {
+        fn input1() -> usize {
             type Input1;
             storage input;
         }
-        fn input2(key: ()) -> usize {
+        fn input2() -> usize {
             type Input2;
             storage input;
         }
     }
 }
 
-fn max(db: &impl MemoizedInputsContext, (): ()) -> usize {
+fn max(db: &impl MemoizedInputsContext) -> usize {
     db.log().add("Max invoked");
-    std::cmp::max(db.input1(()), db.input2(()))
+    std::cmp::max(db.input1(), db.input2())
 }
 
 #[test]
 fn revalidate() {
     let db = &TestContextImpl::default();
 
-    let v = db.max(());
+    let v = db.max();
     assert_eq!(v, 0);
     db.assert_log(&["Max invoked"]);
 
-    let v = db.max(());
+    let v = db.max();
     assert_eq!(v, 0);
     db.assert_log(&[]);
 
     db.query(Input1).set((), 44);
     db.assert_log(&[]);
 
-    let v = db.max(());
+    let v = db.max();
     assert_eq!(v, 44);
     db.assert_log(&["Max invoked"]);
 
-    let v = db.max(());
+    let v = db.max();
     assert_eq!(v, 44);
     db.assert_log(&[]);
 
@@ -52,11 +52,11 @@ fn revalidate() {
     db.query(Input1).set((), 64);
     db.assert_log(&[]);
 
-    let v = db.max(());
+    let v = db.max();
     assert_eq!(v, 66);
     db.assert_log(&["Max invoked"]);
 
-    let v = db.max(());
+    let v = db.max();
     assert_eq!(v, 66);
     db.assert_log(&[]);
 }
@@ -68,12 +68,12 @@ fn set_after_no_change() {
     let db = &TestContextImpl::default();
 
     db.query(Input1).set((), 44);
-    let v = db.max(());
+    let v = db.max();
     assert_eq!(v, 44);
     db.assert_log(&["Max invoked"]);
 
     db.query(Input1).set((), 44);
-    let v = db.max(());
+    let v = db.max();
     assert_eq!(v, 44);
     db.assert_log(&[]);
 }
diff --git a/tests/incremental/memoized_volatile.rs b/tests/incremental/memoized_volatile.rs
index b01c2976..ac0166ba 100644
--- a/tests/incremental/memoized_volatile.rs
+++ b/tests/incremental/memoized_volatile.rs
@@ -5,31 +5,31 @@ salsa::query_group! {
     pub(crate) trait MemoizedVolatileContext: TestContext {
         // Queries for testing a "volatile" value wrapped by
         // memoization.
-        fn memoized2(key: ()) -> usize {
+        fn memoized2() -> usize {
             type Memoized2;
         }
-        fn memoized1(key: ()) -> usize {
+        fn memoized1() -> usize {
             type Memoized1;
         }
-        fn volatile(key: ()) -> usize {
+        fn volatile() -> usize {
             type Volatile;
             storage volatile;
         }
     }
 }
 
-fn memoized2(db: &impl MemoizedVolatileContext, (): ()) -> usize {
+fn memoized2(db: &impl MemoizedVolatileContext) -> usize {
     db.log().add("Memoized2 invoked");
-    db.memoized1(())
+    db.memoized1()
 }
 
-fn memoized1(db: &impl MemoizedVolatileContext, (): ()) -> usize {
+fn memoized1(db: &impl MemoizedVolatileContext) -> usize {
     db.log().add("Memoized1 invoked");
-    let v = db.volatile(());
+    let v = db.volatile();
     v / 2
 }
 
-fn volatile(db: &impl MemoizedVolatileContext, (): ()) -> usize {
+fn volatile(db: &impl MemoizedVolatileContext) -> usize {
     db.log().add("Volatile invoked");
     db.clock().increment()
 }
@@ -40,8 +40,8 @@ fn volatile_x2() {
 
     // Invoking volatile twice doesn't execute twice, because volatile
     // queries are memoized by default.
-    query.volatile(());
-    query.volatile(());
+    query.volatile();
+    query.volatile();
     query.assert_log(&["Volatile invoked"]);
 }
 
@@ -57,20 +57,20 @@ fn volatile_x2() {
 fn revalidate() {
     let query = TestContextImpl::default();
 
-    query.memoized2(());
+    query.memoized2();
     query.assert_log(&["Memoized2 invoked", "Memoized1 invoked", "Volatile invoked"]);
 
-    query.memoized2(());
+    query.memoized2();
     query.assert_log(&[]);
 
     // Second generation: volatile will change (to 1) but memoized1
     // will not (still 0, as 1/2 = 0)
     query.salsa_runtime().next_revision();
 
-    query.memoized2(());
+    query.memoized2();
     query.assert_log(&["Volatile invoked", "Memoized1 invoked"]);
 
-    query.memoized2(());
+    query.memoized2();
     query.assert_log(&[]);
 
     // Third generation: volatile will change (to 2) and memoized1
@@ -78,9 +78,9 @@ fn revalidate() {
     // changed, we now invoke Memoized2.
     query.salsa_runtime().next_revision();
 
-    query.memoized2(());
+    query.memoized2();
     query.assert_log(&["Volatile invoked", "Memoized1 invoked", "Memoized2 invoked"]);
 
-    query.memoized2(());
+    query.memoized2();
     query.assert_log(&[]);
 }
diff --git a/tests/set_unchecked.rs b/tests/set_unchecked.rs
index 3569b687..f27b0c8c 100644
--- a/tests/set_unchecked.rs
+++ b/tests/set_unchecked.rs
@@ -2,29 +2,29 @@ use salsa::Database;
 
 salsa::query_group! {
     trait HelloWorldDatabase: salsa::Database {
-        fn input(key: ()) -> String {
+        fn input() -> String {
             type Input;
             storage input;
         }
 
-        fn length(key: ()) -> usize {
+        fn length() -> usize {
             type Length;
         }
 
-        fn double_length(key: ()) -> usize {
+        fn double_length() -> usize {
             type DoubleLength;
         }
     }
 }
 
-fn length(db: &impl HelloWorldDatabase, (): ()) -> usize {
-    let l = db.input(()).len();
+fn length(db: &impl HelloWorldDatabase) -> usize {
+    let l = db.input().len();
     assert!(l > 0); // not meant to be invoked with no input
     l
 }
 
-fn double_length(db: &impl HelloWorldDatabase, (): ()) -> usize {
-    db.length(()) * 2
+fn double_length(db: &impl HelloWorldDatabase) -> usize {
+    db.length() * 2
 }
 
 #[derive(Default)]
@@ -52,35 +52,35 @@ salsa::database_storage! {
 fn normal() {
     let db = DatabaseStruct::default();
     db.query(Input).set((), format!("Hello, world"));
-    assert_eq!(db.double_length(()), 24);
+    assert_eq!(db.double_length(), 24);
     db.query(Input).set((), format!("Hello, world!"));
-    assert_eq!(db.double_length(()), 26);
+    assert_eq!(db.double_length(), 26);
 }
 
 #[test]
 #[should_panic]
 fn use_without_set() {
     let db = DatabaseStruct::default();
-    db.double_length(());
+    db.double_length();
 }
 
 #[test]
 fn using_set_unchecked_on_input() {
     let db = DatabaseStruct::default();
     db.query(Input).set_unchecked((), format!("Hello, world"));
-    assert_eq!(db.double_length(()), 24);
+    assert_eq!(db.double_length(), 24);
 }
 
 #[test]
 fn using_set_unchecked_on_input_after() {
     let db = DatabaseStruct::default();
     db.query(Input).set((), format!("Hello, world"));
-    assert_eq!(db.double_length(()), 24);
+    assert_eq!(db.double_length(), 24);
 
     // If we use `set_unchecked`, we don't notice that `double_length`
     // is out of date. Oh well, don't do that.
     db.query(Input).set_unchecked((), format!("Hello, world!"));
-    assert_eq!(db.double_length(()), 24);
+    assert_eq!(db.double_length(), 24);
 }
 
 #[test]
@@ -91,5 +91,5 @@ fn using_set_unchecked() {
     // demonstrating that the code never runs.
     db.query(Length).set_unchecked((), 24);
 
-    assert_eq!(db.double_length(()), 48);
+    assert_eq!(db.double_length(), 48);
 }
diff --git a/tests/storage_varieties/queries.rs b/tests/storage_varieties/queries.rs
index 763e48ab..89cfaedf 100644
--- a/tests/storage_varieties/queries.rs
+++ b/tests/storage_varieties/queries.rs
@@ -4,10 +4,10 @@ pub(crate) trait Counter: salsa::Database {
 
 salsa::query_group! {
     pub(crate) trait Database: Counter {
-        fn memoized(key: ()) -> usize {
+        fn memoized() -> usize {
             type Memoized;
         }
-        fn volatile(key: ()) -> usize {
+        fn volatile() -> usize {
             type Volatile;
             storage volatile;
         }
@@ -16,12 +16,12 @@ salsa::query_group! {
 
 /// Because this query is memoized, we only increment the counter
 /// the first time it is invoked.
-fn memoized(db: &impl Database, (): ()) -> usize {
-    db.volatile(())
+fn memoized(db: &impl Database) -> usize {
+    db.volatile()
 }
 
 /// Because this query is volatile, each time it is invoked,
 /// we will increment the counter.
-fn volatile(db: &impl Database, (): ()) -> usize {
+fn volatile(db: &impl Database) -> usize {
     db.increment()
 }
diff --git a/tests/storage_varieties/tests.rs b/tests/storage_varieties/tests.rs
index 486a44fe..ce38ba8e 100644
--- a/tests/storage_varieties/tests.rs
+++ b/tests/storage_varieties/tests.rs
@@ -7,22 +7,22 @@ use salsa::Database as _Database;
 #[test]
 fn memoized_twice() {
     let db = DatabaseImpl::default();
-    let v1 = db.memoized(());
-    let v2 = db.memoized(());
+    let v1 = db.memoized();
+    let v2 = db.memoized();
     assert_eq!(v1, v2);
 }
 
 #[test]
 fn volatile_twice() {
     let db = DatabaseImpl::default();
-    let v1 = db.volatile(());
-    let v2 = db.volatile(()); // volatiles are cached, so 2nd read returns the same
+    let v1 = db.volatile();
+    let v2 = db.volatile(); // volatiles are cached, so 2nd read returns the same
     assert_eq!(v1, v2);
 
     db.salsa_runtime().next_revision(); // clears volatile caches
 
-    let v3 = db.volatile(()); // will re-increment the counter
-    let v4 = db.volatile(()); // second call will be cached
+    let v3 = db.volatile(); // will re-increment the counter
+    let v4 = db.volatile(); // second call will be cached
     assert_eq!(v1 + 1, v3);
     assert_eq!(v3, v4);
 }
@@ -30,10 +30,10 @@ fn volatile_twice() {
 #[test]
 fn intermingled() {
     let db = DatabaseImpl::default();
-    let v1 = db.volatile(());
-    let v2 = db.memoized(());
-    let v3 = db.volatile(()); // cached
-    let v4 = db.memoized(()); // cached
+    let v1 = db.volatile();
+    let v2 = db.memoized();
+    let v3 = db.volatile(); // cached
+    let v4 = db.memoized(); // cached
 
     assert_eq!(v1, v2);
     assert_eq!(v1, v3);
@@ -41,8 +41,8 @@ fn intermingled() {
 
     db.salsa_runtime().next_revision(); // clears volatile caches
 
-    let v5 = db.memoized(()); // re-executes volatile, caches new result
-    let v6 = db.memoized(()); // re-use cached result
+    let v5 = db.memoized(); // re-executes volatile, caches new result
+    let v6 = db.memoized(); // re-use cached result
     assert_eq!(v4 + 1, v5);
     assert_eq!(v5, v6);
 }