diff --git a/src/main/resources/templates/ocaml/test/run.sh b/src/main/resources/templates/ocaml/test/run.sh
index a641fcf98970..3dc4af3ff7cd 100755
--- a/src/main/resources/templates/ocaml/test/run.sh
+++ b/src/main/resources/templates/ocaml/test/run.sh
@@ -3,6 +3,7 @@
 # copy code from the assignment or solution to the appropriate test folder
 cp_code()
 {
+    mv "$2" "$1"
     cd "$1" || exit
     rm ./*.ml >/dev/null 2>&1
     # shellcheck disable=SC2086
@@ -48,9 +49,9 @@ find ../${studentParentWorkingDirectoryName}/ -type l | grep -q . && echo "Canno
 
 # include solution and assignment in the tests
 # this will only pick up *.ml files in the /src folders if other files are required for the tests this needs to be adjusted
-cp_code ${solutionWorkingDirectory}
+cp_code ${solutionWorkingDirectory} solution
 echo 'include Assignment' > ${solutionWorkingDirectory}/solution.ml
-cp_code ${studentParentWorkingDirectoryName}
+cp_code ${studentParentWorkingDirectoryName} assignment
 
 # select if tests are run by generated source code as student toplevel code may run before the tests and be able to spoof a runtime signal
 echo "let runHidden = $RUN_HIDDEN" > test/runHidden.ml
@@ -71,7 +72,7 @@ if ! timeout -s SIGTERM $BUILD_TIMEOUT checker/checker.exe; then
 fi
 # build the student submission
 # don't reference the tests or solution, so that we can show the build output to the student and not leak test / solution code
-if ! timeout -s SIGTERM $BUILD_TIMEOUT dune build --force assignment; then
+if ! timeout -s SIGTERM $BUILD_TIMEOUT dune build --force ${solutionWorkingDirectory}; then
     echo "Unable to build submission, please ensure that your code builds and matches the provided interface" >&2
     exit 0
 fi
diff --git a/src/main/webapp/app/exercises/programming/manage/update/update-components/custom-build-plans/programming-exercise-custom-build-plan.component.ts b/src/main/webapp/app/exercises/programming/manage/update/update-components/custom-build-plans/programming-exercise-custom-build-plan.component.ts
index ef8f0cc14ab2..ca8fecdac875 100644
--- a/src/main/webapp/app/exercises/programming/manage/update/update-components/custom-build-plans/programming-exercise-custom-build-plan.component.ts
+++ b/src/main/webapp/app/exercises/programming/manage/update/update-components/custom-build-plans/programming-exercise-custom-build-plan.component.ts
@@ -49,8 +49,11 @@ export class ProgrammingExerciseCustomBuildPlanComponent implements OnChanges {
             }
         }
         if (this.shouldReplacePlaceholders()) {
-            this.programmingExercise.buildConfig!.buildScript = this.replacePlaceholders(this.originalBuildScript);
-            this.codeChanged(this.programmingExercise.buildConfig?.buildScript || '');
+            const updatedBuildScript = this.replacePlaceholders(this.originalBuildScript);
+            if (updatedBuildScript) {
+                this.programmingExercise.buildConfig!.buildScript = updatedBuildScript;
+                this.codeChanged(this.programmingExercise.buildConfig?.buildScript || '');
+            }
         }
     }
 
@@ -68,9 +71,10 @@ export class ProgrammingExerciseCustomBuildPlanComponent implements OnChanges {
     shouldReplacePlaceholders(): boolean {
         return (
             (!!this.programmingExercise.buildConfig?.assignmentCheckoutPath && this.programmingExercise.buildConfig?.assignmentCheckoutPath !== '') ||
-            (!!this.programmingExercise.buildConfig?.testCheckoutPath && this.programmingExercise.buildConfig?.testCheckoutPath !== '') ||
-            !!this.programmingExercise.buildConfig?.buildScript?.includes('${studentParentWorkingDirectoryName}') ||
-            !!this.programmingExercise.buildConfig?.buildScript?.includes('${testWorkingDirectory}')
+            (!!this.programmingExercise.buildConfig?.testCheckoutPath &&
+                this.programmingExercise.buildConfig?.testCheckoutPath !== '' &&
+                (!!this.programmingExercise.buildConfig?.buildScript?.includes('${studentParentWorkingDirectoryName}') ||
+                    !!this.programmingExercise.buildConfig?.buildScript?.includes('${testWorkingDirectory}')))
         );
     }