diff --git a/build-logic/convention/src/main/kotlin/com/google/samples/apps/nowinandroid/Jacoco.kt b/build-logic/convention/src/main/kotlin/com/google/samples/apps/nowinandroid/Jacoco.kt
index 639e3c482..f8d8d567c 100644
--- a/build-logic/convention/src/main/kotlin/com/google/samples/apps/nowinandroid/Jacoco.kt
+++ b/build-logic/convention/src/main/kotlin/com/google/samples/apps/nowinandroid/Jacoco.kt
@@ -90,15 +90,16 @@ internal fun Project.configureJacoco(
                     html.required = true
                 }
 
-                // Collect all java and kotlin source directories from the variant's source sets
-                fun SourceDirectories.Flat.toFilePaths(): Provider<List<String>> = this
-                    .all
-                    .map { directories -> directories.map { it.asFile.path } }
+                fun SourceDirectories.Flat?.toFilePaths(): Provider<List<String>> = this
+                    ?.all
+                    ?.map { directories -> directories.map { it.asFile.path } }
+                    ?: provider { emptyList() }
+                operator fun Provider<List<String>>.plus(other: Provider<List<String>>) =
+                    zip(other) { first, second -> first + second }
                 sourceDirectories.setFrom(
                     files(
-                        variant.sources.java?.toFilePaths(),
-                        variant.sources.kotlin?.toFilePaths()
-                    )
+                        variant.sources.java.toFilePaths() + variant.sources.kotlin.toFilePaths()
+                    ),
                 )
 
                 executionData.setFrom(