diff --git a/wot-dijkstra/src/test/kotlin/org/pgpainless/wot/network/RegexSetTest.kt b/wot-dijkstra/src/test/kotlin/org/pgpainless/wot/network/RegexSetTest.kt
index 84a60dfb..31f00efd 100644
--- a/wot-dijkstra/src/test/kotlin/org/pgpainless/wot/network/RegexSetTest.kt
+++ b/wot-dijkstra/src/test/kotlin/org/pgpainless/wot/network/RegexSetTest.kt
@@ -2,6 +2,7 @@ package org.pgpainless.wot.network
 
 import org.junit.jupiter.api.Test
 import org.pgpainless.wot.dsl.NetworkDSL
+import kotlin.test.assertEquals
 import kotlin.test.assertFalse
 import kotlin.test.assertTrue
 
@@ -64,4 +65,23 @@ class RegexSetTest: NetworkDSL {
         assertTrue { regex.matches("Alice <alice@pgpainless.org>") }
         assertFalse { regex.matches("<alice@pgpainless\\.org>") }
     }
+
+    @Test
+    fun `verify that wildcard()_toString() equals empty string`() {
+        val regex = RegexSet.wildcard()
+        assertEquals("", regex.toString())
+    }
+
+    @Test
+    fun `verify that single regex _toString() returns the regex`() {
+        val regex = domainRegex("pgpainless.org")
+        assertEquals("<[^>]+[@.]pgpainless\\.org>\$", regex.toString())
+    }
+
+    @Test
+    fun `verify that multiple regex _toString returns comma separated values`() {
+        val list = listOf("<[^>]+[@.]pgpainless\\.org>\$", "<[^>]+[@.]example\\.com>\$")
+        val regex = RegexSet.fromExpressionList(list)
+        assertEquals("<[^>]+[@.]pgpainless\\.org>\$, <[^>]+[@.]example\\.com>\$", regex.toString())
+    }
 }
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