diff --git a/alib2std/src/extensions/foreach.hpp b/alib2std/src/extensions/foreach.hpp
index e036cc8467201ee6942c92547a6a24b19a893608..7937c60aadb6e44e6b7d62ba4b897f9ff0a41346 100644
--- a/alib2std/src/extensions/foreach.hpp
+++ b/alib2std/src/extensions/foreach.hpp
@@ -66,14 +66,14 @@ public:
 		return *this;
 	}
 
-	const_pair_foreach_iterator& operator++(int) {
+	const_pair_foreach_iterator operator++(int) {
 		const_pair_foreach_iterator temp = *this;
 		++current1;
 		++current2;
 		return temp;
 	}
 
-	const_pair_foreach_iterator& operator--(int) {
+	const_pair_foreach_iterator operator--(int) {
 		const_pair_foreach_iterator temp = *this;
 		--current1;
 		--current2;
diff --git a/alib2std/src/extensions/set.hpp b/alib2std/src/extensions/set.hpp
index 45d73931d03c88bd4cbfa06f10826822a47bed67..751eaf4694d421e566f1717f4b1de3d64f9ec3fe 100644
--- a/alib2std/src/extensions/set.hpp
+++ b/alib2std/src/extensions/set.hpp
@@ -101,13 +101,13 @@ public:
 		return *this;
 	}
 
-	set_move_iterator& operator++(int) {
+	set_move_iterator operator++(int) {
 		set_move_iterator temp = *this;
 		++current;
 		return temp;
 	}
 
-	set_move_iterator& operator--(int) {
+	set_move_iterator operator--(int) {
 		set_move_iterator temp = *this;
 		--current;
 		return temp;
diff --git a/alib2std/src/extensions/vector.hpp b/alib2std/src/extensions/vector.hpp
index ec101e339a4697cebd0b60b4c4ef79c13e5dd8a0..7f6b0d59a9a58a66eebced02552f7eb34e519acd 100644
--- a/alib2std/src/extensions/vector.hpp
+++ b/alib2std/src/extensions/vector.hpp
@@ -56,13 +56,13 @@ public:
 		return *this;
 	}
 
-	ptr_vector_iterator& operator++(int) {
+	ptr_vector_iterator operator++(int) {
 		ptr_vector_iterator temp = *this;
 		++current;
 		return temp;
 	}
 
-	ptr_vector_iterator& operator--(int) {
+	ptr_vector_iterator operator--(int) {
 		ptr_vector_iterator temp = *this;
 		--current;
 		return temp;