diff --git a/of.go b/of.go
index da5a7cd..11959fb 100644
--- a/of.go
+++ b/of.go
@@ -59,7 +59,7 @@ func OfFunc[T any](ctx context.Context, buffer int, f func() T) <-chan T {
 func OfMap[K comparable, V, T any](m map[K]V, unmapper func(K, V) T) <-chan T {
 	out := make(chan T, len(m))
 
-	defer func() {
+	go func() {
 		defer close(out)
 		for k, v := range m {
 			out <- unmapper(k, v)
@@ -73,7 +73,7 @@ func OfMap[K comparable, V, T any](m map[K]V, unmapper func(K, V) T) <-chan T {
 func OfSeq[T any](seq iter.Seq[T]) <-chan T {
 	out := make(chan T, 10)
 
-	defer func() {
+	go func() {
 		defer close(out)
 		for v := range seq {
 			out <- v
@@ -88,7 +88,7 @@ func OfSeq[T any](seq iter.Seq[T]) <-chan T {
 func OfSeq2[K comparable, V, T any](seq iter.Seq2[K, V], unmapper func(K, V) T) <-chan T {
 	out := make(chan T, 10)
 
-	defer func() {
+	go func() {
 		defer close(out)
 		for key, value := range seq {
 			out <- unmapper(key, value)