diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/BooleanConditionController.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/BooleanConditionController.java
index fac99b5..ddcb880 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/BooleanConditionController.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/BooleanConditionController.java
@@ -25,11 +25,11 @@ public class BooleanConditionController {
     @Autowired BooleanConditionRepository booleanConditionRepository;
 
     @GetMapping("/{automationId}")
-    public List<BooleanCondition<?>> getAll(@PathVariable long automationId) {
+    public List<BooleanCondition> getAll(@PathVariable long automationId) {
         return booleanConditionRepository.findAllByAutomationId(automationId);
     }
 
-    private BooleanCondition<?> save(BooleanCondition<?> newRL, BooleanConditionSaveRequest s) {
+    private BooleanCondition save(BooleanCondition newRL, BooleanConditionSaveRequest s) {
         newRL.setDeviceId(s.getDeviceId());
         newRL.setAutomationId(s.getAutomationId());
         newRL.setOn(s.isOn());
@@ -38,13 +38,13 @@ public class BooleanConditionController {
     }
 
     @PostMapping
-    public BooleanCondition<?> create(
+    public BooleanCondition create(
             @Valid @RequestBody BooleanConditionSaveRequest booleanTriggerSaveRequest) {
-        return save(new BooleanCondition<>(), booleanTriggerSaveRequest);
+        return save(new BooleanCondition(), booleanTriggerSaveRequest);
     }
 
     @PutMapping
-    public BooleanCondition<?> update(
+    public BooleanCondition update(
             @Valid @RequestBody BooleanConditionSaveRequest booleanTriggerSaveRequest)
             throws NotFoundException {
         return save(
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RangeConditionController.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RangeConditionController.java
index 25491b0..5055c61 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RangeConditionController.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RangeConditionController.java
@@ -25,11 +25,11 @@ public class RangeConditionController {
     @Autowired RangeConditionRepository rangeConditionRepository;
 
     @GetMapping("/{automationId}")
-    public List<RangeCondition<?>> getAll(@PathVariable long automationId) {
+    public List<RangeCondition> getAll(@PathVariable long automationId) {
         return rangeConditionRepository.findAllByAutomationId(automationId);
     }
 
-    private RangeCondition<?> save(RangeCondition<?> newRL, RangeConditionSaveRequest s) {
+    private RangeCondition save(RangeCondition newRL, RangeConditionSaveRequest s) {
         newRL.setDeviceId(s.getDeviceId());
         newRL.setAutomationId(s.getAutomationId());
         newRL.setOperator(s.getOperator());
@@ -39,13 +39,13 @@ public class RangeConditionController {
     }
 
     @PostMapping
-    public RangeCondition<?> create(
+    public RangeCondition create(
             @Valid @RequestBody RangeConditionSaveRequest booleanTriggerSaveRequest) {
-        return save(new RangeCondition<>(), booleanTriggerSaveRequest);
+        return save(new RangeCondition(), booleanTriggerSaveRequest);
     }
 
     @PutMapping
-    public RangeCondition<?> update(
+    public RangeCondition update(
             @Valid @RequestBody RangeConditionSaveRequest booleanTriggerSaveRequest)
             throws NotFoundException {
         return save(
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/dto/AutomationFastUpdateRequest.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/dto/AutomationFastUpdateRequest.java
index 5283ec3..bb90896 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/dto/AutomationFastUpdateRequest.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/dto/AutomationFastUpdateRequest.java
@@ -62,33 +62,33 @@ public class AutomationFastUpdateRequest {
         }
     }
 
-    public abstract class ConditionDTO {
+    public abstract static class ConditionDTO {
         @NotNull public long deviceId;
 
         public abstract Condition<?> toModel();
     }
 
-    public class BooleanConditionDTO extends ConditionDTO {
+    public static class BooleanConditionDTO extends ConditionDTO {
 
         @NotNull public boolean on;
 
         @Override
         public Condition<?> toModel() {
-            BooleanCondition<?> t = new BooleanCondition<>();
+            BooleanCondition t = new BooleanCondition();
             t.setDeviceId(this.deviceId);
             t.setOn(this.on);
             return t;
         }
     }
 
-    public class RangeConditionDTO extends ConditionDTO {
+    public static class RangeConditionDTO extends ConditionDTO {
 
         @NotNull RangeCondition.Operator operator;
         @NotNull double range;
 
         @Override
         public Condition<?> toModel() {
-            RangeCondition<?> t = new RangeCondition<>();
+            RangeCondition t = new RangeCondition();
             t.setDeviceId(this.deviceId);
             t.setOperator(this.operator);
             t.setRange(this.range);
@@ -96,7 +96,7 @@ public class AutomationFastUpdateRequest {
         }
     }
 
-    public class ThermostatConditionDTO extends ConditionDTO {
+    public static class ThermostatConditionDTO extends ConditionDTO {
 
         @NotNull ThermostatCondition.Operator operator;
         @NotNull private Thermostat.Mode mode;
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/BooleanCondition.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/BooleanCondition.java
index 5b3f1e3..22ac7a2 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/BooleanCondition.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/BooleanCondition.java
@@ -4,8 +4,7 @@ import javax.persistence.Column;
 import javax.persistence.Entity;
 
 @Entity
-public class BooleanCondition<D extends Device & BooleanTriggerable>
-        extends Condition<D> { // TODO add interface to type constraints
+public class BooleanCondition extends Condition<BooleanTriggerable> {
 
     @Column(name = "switchable_on")
     private boolean on;
@@ -22,10 +21,6 @@ public class BooleanCondition<D extends Device & BooleanTriggerable>
         this.on = on;
     }
 
-    public boolean check(boolean on) {
-        return this.on == on;
-    }
-
     @Override
     public boolean triggered() {
         return this.getDevice().readTriggerState() == isOn();
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/BooleanConditionRepository.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/BooleanConditionRepository.java
index c564c41..539eb6d 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/BooleanConditionRepository.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/BooleanConditionRepository.java
@@ -3,8 +3,7 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.models;
 import java.util.List;
 import org.springframework.data.repository.query.Param;
 
-public interface BooleanConditionRepository
-        extends ConditionRepository<BooleanCondition<? extends Device>> {
+public interface BooleanConditionRepository extends ConditionRepository<BooleanCondition> {
 
-    List<BooleanCondition<?>> findAllByAutomationId(@Param("automationId") long automationId);
+    List<BooleanCondition> findAllByAutomationId(@Param("automationId") long automationId);
 }
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Condition.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Condition.java
index 859730b..08b2db8 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Condition.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Condition.java
@@ -10,10 +10,9 @@ import javax.persistence.Id;
 import javax.persistence.JoinColumn;
 import javax.persistence.ManyToOne;
 import javax.persistence.Transient;
-import javax.validation.constraints.NotNull;
 
 @Entity
-public abstract class Condition<D extends Device> {
+public abstract class Condition<D> {
 
     @Transient private String kind;
 
@@ -41,7 +40,6 @@ public abstract class Condition<D extends Device> {
      * from a REST call.
      */
     @Column(name = "device_id", nullable = false)
-    @NotNull
     private Long deviceId;
 
     @ManyToOne
@@ -50,7 +48,6 @@ public abstract class Condition<D extends Device> {
     private Automation automation;
 
     @Column(name = "automation_id", nullable = false)
-    @NotNull
     private Long automationId;
 
     public abstract boolean triggered();
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/RangeCondition.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/RangeCondition.java
index 7ad1a8d..f3e4bce 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/RangeCondition.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/RangeCondition.java
@@ -7,10 +7,10 @@ import javax.persistence.Entity;
 import javax.validation.constraints.NotNull;
 
 @Entity
-public class RangeCondition<D extends Device & RangeTriggerable> extends Condition<D> {
+public class RangeCondition extends Condition<RangeTriggerable> {
 
     public RangeCondition() {
-        super("booleanCondition");
+        super("rangeCondition");
     }
 
     public enum Operator {
@@ -26,7 +26,6 @@ public class RangeCondition<D extends Device & RangeTriggerable> extends Conditi
         GREATER_EQUAL
     }
 
-    @NotNull
     @Column(nullable = false)
     private RangeCondition.Operator operator;
 
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/RangeConditionRepository.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/RangeConditionRepository.java
index 1ed6aa3..451d4a7 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/RangeConditionRepository.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/RangeConditionRepository.java
@@ -3,8 +3,6 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.models;
 import java.util.List;
 import org.springframework.data.repository.query.Param;
 
-public interface RangeConditionRepository
-        extends ConditionRepository<RangeCondition<? extends Device>> {
-
-    List<RangeCondition<?>> findAllByAutomationId(@Param("automationId") long automationId);
+public interface RangeConditionRepository extends ConditionRepository<RangeCondition> {
+    List<RangeCondition> findAllByAutomationId(@Param("automationId") long automationId);
 }