diff --git a/drools/src/main/resources/courseScheduleSolverConfigDrools.xml b/drools/src/main/resources/courseScheduleSolverConfigDrools.xml
index 7cf95fdcd3..74112d9c7d 100644
--- a/drools/src/main/resources/courseScheduleSolverConfigDrools.xml
+++ b/drools/src/main/resources/courseScheduleSolverConfigDrools.xml
@@ -1,7 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <solver>
-    <scanAnnotatedClasses/>
-
+   
+    <solutionClass>com.baeldung.drools.optaplanner.CourseSchedule</solutionClass>
+    <entityClass>com.baeldung.drools.optaplanner.Lecture</entityClass>
+    
     <scoreDirectorFactory>
         <scoreDrl>courseSchedule.drl</scoreDrl>
     </scoreDirectorFactory>
diff --git a/drools/src/main/resources/courseScheduleSolverConfiguration.xml b/drools/src/main/resources/courseScheduleSolverConfiguration.xml
index dfedb8f2fd..4214b0943a 100644
--- a/drools/src/main/resources/courseScheduleSolverConfiguration.xml
+++ b/drools/src/main/resources/courseScheduleSolverConfiguration.xml
@@ -1,7 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <solver>
-    <scanAnnotatedClasses/>
 
+    <solutionClass>com.baeldung.drools.optaplanner.CourseSchedule</solutionClass>
+    <entityClass>com.baeldung.drools.optaplanner.Lecture</entityClass>
+    
     <scoreDirectorFactory>
         <easyScoreCalculatorClass>com.baeldung.drools.optaplanner.ScoreCalculator</easyScoreCalculatorClass>
     </scoreDirectorFactory>
diff --git a/drools/src/test/java/com/baeldung/drools/optaplanner/OptaPlannerUnitTest.java b/drools/src/test/java/com/baeldung/drools/optaplanner/OptaPlannerUnitTest.java
index 2165cdda1f..36b24349c7 100644
--- a/drools/src/test/java/com/baeldung/drools/optaplanner/OptaPlannerUnitTest.java
+++ b/drools/src/test/java/com/baeldung/drools/optaplanner/OptaPlannerUnitTest.java
@@ -7,7 +7,6 @@ import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.optaplanner.core.api.solver.Solver;
 import org.optaplanner.core.api.solver.SolverFactory;
-import org.optaplanner.core.config.solver.SolverConfig;
 
 public class OptaPlannerUnitTest {
 
@@ -28,8 +27,7 @@ public class OptaPlannerUnitTest {
 
     @Test
     public void test_whenCustomJavaSolver() {
-        SolverConfig solverConfig = SolverConfig.createFromXmlResource("courseScheduleSolverConfiguration.xml");
-        SolverFactory<CourseSchedule> solverFactory = SolverFactory.create(solverConfig);
+        SolverFactory<CourseSchedule> solverFactory = SolverFactory.createFromXmlResource("courseScheduleSolverConfiguration.xml");
         Solver<CourseSchedule> solver = solverFactory.buildSolver();
         CourseSchedule solvedCourseSchedule = solver.solve(unsolvedCourseSchedule);
 
@@ -39,7 +37,6 @@ public class OptaPlannerUnitTest {
 
     @Test
     public void test_whenDroolsSolver() {
-
         SolverFactory<CourseSchedule> solverFactory = SolverFactory.createFromXmlResource("courseScheduleSolverConfigDrools.xml");
         Solver<CourseSchedule> solver = solverFactory.buildSolver();
         CourseSchedule solvedCourseSchedule = solver.solve(unsolvedCourseSchedule);
diff --git a/pom.xml b/pom.xml
index e330fd81c1..bd6c43ad3d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -904,13 +904,13 @@
                 <module>core-java-modules/core-java-networking-3</module>
                 <module>core-java-modules/core-java-strings</module>
                 <module>core-java-modules/core-java-httpclient</module>
-				        <module>custom-pmd</module>
+                <module>custom-pmd</module>
                 <module>spring-core-6</module>
                 <module>data-structures</module>
                 <module>ddd-contexts</module>
                 <module>deeplearning4j</module>
                 <module>docker-modules</module>
-				        <module>drools</module>
+                <module>drools</module>
                 <module>guava-modules</module>
                 <module>apache-httpclient-2</module>
                 <module>kubernetes-modules/kubernetes-spring</module>
@@ -1118,13 +1118,13 @@
                 <module>core-java-modules/core-java-networking-3</module>
                 <module>core-java-modules/core-java-strings</module>
                 <module>core-java-modules/core-java-httpclient</module>
-				        <module>custom-pmd</module>
+                <module>custom-pmd</module>
                 <module>spring-core-6</module>
                 <module>data-structures</module>
                 <module>ddd-contexts</module>
                 <module>deeplearning4j</module>
                 <module>docker-modules</module>
-				        <module>drools</module>
+                <module>drools</module>
                 <module>guava-modules</module>
                 <module>apache-httpclient-2</module>
                 <module>kubernetes-modules/kubernetes-spring</module>