diff --git a/rxandroidble/src/test/groovy/com/polidea/rxandroidble2/exceptions/BleScanExceptionTest.groovy b/rxandroidble/src/test/groovy/com/polidea/rxandroidble2/exceptions/BleScanExceptionTest.groovy
deleted file mode 100644
index 6041c00d0..000000000
--- a/rxandroidble/src/test/groovy/com/polidea/rxandroidble2/exceptions/BleScanExceptionTest.groovy
+++ /dev/null
@@ -1,23 +0,0 @@
-package com.polidea.rxandroidble2.exceptions
-
-import spock.lang.Specification
-
-import static com.polidea.rxandroidble2.exceptions.BleScanException.BLUETOOTH_DISABLED
-
-/**
- * Tests BleScanException
- */
-class BleScanExceptionTest extends Specification {
-
-    BleScanException objectUnderTest
-
-    def "toString should include message"() {
-
-        when:
-        objectUnderTest = new BleScanException(BLUETOOTH_DISABLED)
-
-        then:
-        assert objectUnderTest.toString() ==
-                "com.polidea.rxandroidble2.exceptions.BleScanException: Bluetooth disabled (code 1)"
-    }
-}
diff --git a/rxandroidble/src/test/java/com/polidea/rxandroidble2/exceptions/BleScanExceptionTest.java b/rxandroidble/src/test/java/com/polidea/rxandroidble2/exceptions/BleScanExceptionTest.java
new file mode 100644
index 000000000..d4d46ba4d
--- /dev/null
+++ b/rxandroidble/src/test/java/com/polidea/rxandroidble2/exceptions/BleScanExceptionTest.java
@@ -0,0 +1,17 @@
+package com.polidea.rxandroidble2.exceptions;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class BleScanExceptionTest {
+
+    @Test
+    public void toStringShouldContainMessage() {
+        // given
+        BleScanException out = new BleScanException(BleScanException.BLUETOOTH_DISABLED);
+
+        // expect
+        assertEquals(out.toString(), "sscom.polidea.rxandroidble2.exceptions.BleScanException: Bluetooth disabled (code 1)");
+    }
+}