diff --git a/apps/UnitTestsApp/src/UnitTests.cpp b/apps/UnitTestsApp/src/UnitTests.cpp
index 0645f94a..9136becc 100644
--- a/apps/UnitTestsApp/src/UnitTests.cpp
+++ b/apps/UnitTestsApp/src/UnitTests.cpp
@@ -786,9 +786,9 @@ TEST(TestBisimilar, MFA_Bisimilar) {
 	ASSERT_TRUE(MemoryFiniteAutomaton::bisimilar(BackRefRegex("[aa*]:1a&1").to_mfa_additional(),
 												 BackRefRegex("a[a*a]:1&1").to_mfa_additional())
 					.value());
-	//	ASSERT_FALSE(MemoryFiniteAutomaton::bisimilar(BackRefRegex("[a*]:1a*&1").to_mfa_additional(),
-	//												  BackRefRegex("a*[a*]:1&1").to_mfa_additional())
-	//					 .value());
+	ASSERT_FALSE(MemoryFiniteAutomaton::bisimilar(BackRefRegex("[a*]:1a*&1").to_mfa_additional(),
+												  BackRefRegex("a*[a*]:1&1").to_mfa_additional())
+					 .value());
 	ASSERT_TRUE(MemoryFiniteAutomaton::bisimilar(BackRefRegex("[ab]:2cab&2").to_mfa_additional(),
 												 BackRefRegex("abc[ab]:2&2").to_mfa_additional())
 					.value());
diff --git a/libs/Objects/include/Objects/MemoryCommon.h b/libs/Objects/include/Objects/MemoryCommon.h
index c2a98fe1..79c0729c 100644
--- a/libs/Objects/include/Objects/MemoryCommon.h
+++ b/libs/Objects/include/Objects/MemoryCommon.h
@@ -30,6 +30,7 @@ struct CaptureGroup {
 		int index;
 		int class_num;
 
+		static const int reset_class = -1;
 		bool operator==(const State& other) const;
 
 		struct Hasher {
diff --git a/libs/Objects/src/MemoryCommon.cpp b/libs/Objects/src/MemoryCommon.cpp
index f8da4c06..0f5ec97b 100644
--- a/libs/Objects/src/MemoryCommon.cpp
+++ b/libs/Objects/src/MemoryCommon.cpp
@@ -42,8 +42,9 @@ CaptureGroup::CaptureGroup(int cell, const std::vector<std::vector<int>>& _trace
 	for (const auto& trace : _traces) {
 		traces.insert(trace);
 		for (auto st : trace) {
-			states.insert({st, _state_classes[st]});
-			state_classes.insert(_state_classes[st]);
+			int class_num = (trace.size() > 1) ? _state_classes[st] : State::reset_class;
+			states.insert({st, class_num});
+			state_classes.insert(class_num);
 		}
 	}
 }
@@ -56,7 +57,7 @@ std::unordered_set<int> CaptureGroup::get_states_diff(
 	const std::unordered_set<int>& other_state_classes) const {
 	std::unordered_set<int> res;
 	for (auto st : states)
-		if (!other_state_classes.count(st.class_num))
+		if (st.class_num != State::reset_class && !other_state_classes.count(st.class_num))
 			res.insert(st.index);
 
 	for (const auto& trace : traces)
diff --git a/libs/Objects/src/MemoryFiniteAutomaton.cpp b/libs/Objects/src/MemoryFiniteAutomaton.cpp
index 76dabd27..63b96ff8 100644
--- a/libs/Objects/src/MemoryFiniteAutomaton.cpp
+++ b/libs/Objects/src/MemoryFiniteAutomaton.cpp
@@ -1534,7 +1534,7 @@ optional<bool> MemoryFiniteAutomaton::bisimilarity_checker(const MemoryFiniteAut
 			CGs2_fa(fas[1].get_subautomaton(CGs2[0]));
 		for (int i = 1; i < CGs1.size(); i++)
 			CGs1_fa = FiniteAutomaton::uunion(CGs1_fa, fas[0].get_subautomaton(CGs1[i]));
-		for (int i = 1; i < CGs1.size(); i++)
+		for (int i = 1; i < CGs2.size(); i++)
 			CGs2_fa = FiniteAutomaton::uunion(CGs2_fa, fas[1].get_subautomaton(CGs2[i]));
 		if (!FiniteAutomaton::equivalent(CGs1_fa, CGs2_fa))
 			return false;