diff --git a/promql/engine.go b/promql/engine.go
index f61aa1c26..63c0b9606 100644
--- a/promql/engine.go
+++ b/promql/engine.go
@@ -248,7 +248,7 @@ type query struct {
 	stmt Statement
 	// Timer stats for the query execution.
 	stats *stats.TimerGroup
-	// Cancelation function for the query.
+	// Cancellation function for the query.
 	cancel func()
 
 	// The engine against which the query is executed.
@@ -732,7 +732,7 @@ func (ev *evaluator) Eval(expr Expr) (v model.Value, err error) {
 // eval evaluates the given expression as the given AST expression node requires.
 func (ev *evaluator) eval(expr Expr) model.Value {
 	// This is the top-level evaluation method.
-	// Thus, we check for timeout/cancelation here.
+	// Thus, we check for timeout/cancellation here.
 	if err := contextDone(ev.ctx, "expression evaluation"); err != nil {
 		ev.error(err)
 	}
diff --git a/promql/engine_test.go b/promql/engine_test.go
index 134f417f3..986240e96 100644
--- a/promql/engine_test.go
+++ b/promql/engine_test.go
@@ -190,7 +190,7 @@ func TestEngineShutdown(t *testing.T) {
 		t.Fatalf("expected error on querying with canceled context but got none")
 	}
 	if _, ok := res2.Err.(ErrQueryCanceled); !ok {
-		t.Fatalf("expected cancelation error, got %q", res2.Err)
+		t.Fatalf("expected cancellation error, got %q", res2.Err)
 	}
 }
 
diff --git a/promql/functions.go b/promql/functions.go
index d496fb958..e1168807b 100644
--- a/promql/functions.go
+++ b/promql/functions.go
@@ -150,7 +150,7 @@ func funcIrate(ev *evaluator, args Expressions) model.Value {
 	return instantValue(ev, args[0], true)
 }
 
-// === idelta(node model.ValMatric) Vector ===
+// === idelta(node model.ValMatrix) Vector ===
 func funcIdelta(ev *evaluator, args Expressions) model.Value {
 	return instantValue(ev, args[0], false)
 }