diff --git a/src/test/java/edu/kit/typicalc/model/TreeTest.java b/src/test/java/edu/kit/typicalc/model/TreeTest.java
index 2ff3687..baed83a 100644
--- a/src/test/java/edu/kit/typicalc/model/TreeTest.java
+++ b/src/test/java/edu/kit/typicalc/model/TreeTest.java
@@ -3,12 +3,15 @@ package edu.kit.typicalc.model;
 import edu.kit.typicalc.model.step.*;
 import edu.kit.typicalc.model.term.*;
 import edu.kit.typicalc.model.type.*;
+import nl.jqno.equalsverifier.EqualsVerifier;
+import nl.jqno.equalsverifier.Warning;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
 import java.util.*;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class TreeTest {
 
@@ -164,4 +167,12 @@ class TreeTest {
         constraints.add(varRightConstraint);
         assertEquals(constraints, tree.getConstraints());
     }
+
+    @Test
+    void equalsTest() {
+        EqualsVerifier.forClass(Tree.class).usingGetClass()
+                .withIgnoredFields("typeVarFactory", "stepFactory")
+                .suppress(Warning.NONFINAL_FIELDS)
+                .verify();
+    }
 }
diff --git a/src/test/java/edu/kit/typicalc/model/TypeInferenceResultTest.java b/src/test/java/edu/kit/typicalc/model/TypeInferenceResultTest.java
index 693df37..d79484f 100644
--- a/src/test/java/edu/kit/typicalc/model/TypeInferenceResultTest.java
+++ b/src/test/java/edu/kit/typicalc/model/TypeInferenceResultTest.java
@@ -4,6 +4,7 @@ import edu.kit.typicalc.model.type.FunctionType;
 import edu.kit.typicalc.model.type.Type;
 import edu.kit.typicalc.model.type.TypeVariable;
 import edu.kit.typicalc.model.type.TypeVariableKind;
+import nl.jqno.equalsverifier.EqualsVerifier;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
@@ -71,4 +72,9 @@ class TypeInferenceResultTest {
         Type expectedType = new FunctionType(A_2, new FunctionType(new FunctionType(A_2, A_5), A_5));
         assertEquals(expectedType, result.getType());
     }
+
+    @Test
+    void equalsTest() {
+        EqualsVerifier.forClass(TypeInferenceResult.class).usingGetClass().verify();
+    }
 }
diff --git a/src/test/java/edu/kit/typicalc/model/TypeInfererLetTest.java b/src/test/java/edu/kit/typicalc/model/TypeInfererLetTest.java
index 7b1c3c2..c35ce42 100644
--- a/src/test/java/edu/kit/typicalc/model/TypeInfererLetTest.java
+++ b/src/test/java/edu/kit/typicalc/model/TypeInfererLetTest.java
@@ -6,6 +6,7 @@ import edu.kit.typicalc.model.term.VarTerm;
 import edu.kit.typicalc.model.type.TypeAbstraction;
 import edu.kit.typicalc.model.type.TypeVariable;
 import edu.kit.typicalc.model.type.TypeVariableKind;
+import nl.jqno.equalsverifier.EqualsVerifier;
 import org.junit.jupiter.api.Test;
 
 import java.util.*;
@@ -45,4 +46,9 @@ class TypeInfererLetTest {
                 = new ArrayList<>(Collections.singletonList(new Constraint(variable2, generated1)));
         assertEquals(expectedLetConstraints, typeInfererLet.getLetConstraints());
     }
+
+    @Test
+    void equalsTest() {
+        EqualsVerifier.forClass(TypeInfererLet.class).usingGetClass().verify();
+    }
 }
diff --git a/src/test/java/edu/kit/typicalc/model/UnificationTest.java b/src/test/java/edu/kit/typicalc/model/UnificationTest.java
index 3ee1b54..814ba70 100644
--- a/src/test/java/edu/kit/typicalc/model/UnificationTest.java
+++ b/src/test/java/edu/kit/typicalc/model/UnificationTest.java
@@ -4,6 +4,7 @@ import edu.kit.typicalc.model.type.FunctionType;
 import edu.kit.typicalc.model.type.TypeVariable;
 import edu.kit.typicalc.model.type.TypeVariableKind;
 import edu.kit.typicalc.util.Result;
+import nl.jqno.equalsverifier.EqualsVerifier;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayDeque;
@@ -101,4 +102,9 @@ class UnificationTest {
                 UnificationError.INFINITE_TYPE
         ), new ArrayList<>()), steps.get(1));
     }
+
+    @Test
+    void equalsTest() {
+        EqualsVerifier.forClass(Unification.class).usingGetClass().verify();
+    }
 }