diff --git a/alib2data/test-src/label/LabelTest.cpp b/alib2data/test-src/label/LabelTest.cpp
index ca5436e1d78ebdb0076b865e72fbaef92666ee07..1c98b77cee62a4781a1ee8b65355fac0a77b1386 100644
--- a/alib2data/test-src/label/LabelTest.cpp
+++ b/alib2data/test-src/label/LabelTest.cpp
@@ -14,6 +14,7 @@
 #include "label/LabelToXMLComposer.h"
 
 #include "factory/DataFactory.hpp"
+#include <algorithm>
 
 #define CPPUNIT_EXCLUSIVE_OR(x, y) CPPUNIT_ASSERT((!(x) && (y)) || ((x) && !(y)))
 
@@ -145,3 +146,32 @@ void LabelTest::testOrder() {
 	CPPUNIT_EXCLUSIVE_OR( s1 < c1, c1 < s1);
 }
 
+void LabelTest::testInSet() {
+	{
+		std::set<std::string> set1 { "a", "b", "c" };
+		std::set<std::string> set2 { "a" };
+		std::set<std::string> set3;
+
+		std::set_difference(set1.begin(), set1.end(), set2.begin(), set2.end(), std::insert_iterator<std::set<std::string>>(set3, set3.begin()));
+		for(const auto& item : set2) {
+			set1.erase(item);
+		}
+
+		CPPUNIT_ASSERT(set1.size() == 2);
+		CPPUNIT_ASSERT(set3.size() == 2);
+	}
+	{
+		std::set<label::Label> set1 { label::labelFrom('a'), label::labelFrom('b'), label::labelFrom('c') };
+		std::set<label::Label> set2 { label::labelFrom('a') };
+		std::set<label::Label> set3;
+
+		std::set_difference(set1.begin(), set1.end(), set2.begin(), set2.end(), std::insert_iterator<std::set<label::Label>>(set3, set3.begin()));
+		for(const auto& item : set2) {
+			set1.erase(item);
+		}
+
+		CPPUNIT_ASSERT(set1.size() == 2);
+		CPPUNIT_ASSERT(set3.size() == 2);
+	}
+}
+
diff --git a/alib2data/test-src/label/LabelTest.h b/alib2data/test-src/label/LabelTest.h
index 23706a7e852538bc3916af6978e6fb2f5b4e8ad4..2068b43252a011833810cedd6cbb12b2d82d3e82 100644
--- a/alib2data/test-src/label/LabelTest.h
+++ b/alib2data/test-src/label/LabelTest.h
@@ -10,6 +10,7 @@ class LabelTest : public CppUnit::TestFixture
 	CPPUNIT_TEST( testEqual );
 	CPPUNIT_TEST( testXMLParser );
 	CPPUNIT_TEST( testOrder );
+	CPPUNIT_TEST( testInSet );
 	CPPUNIT_TEST_SUITE_END();
 
 public:
@@ -20,6 +21,7 @@ public:
 	void testEqual();
 	void testXMLParser();
 	void testOrder();
+	void testInSet();
 };
 
 #endif	// LABEL_TEST_H_