diff --git a/src/test/java/org/eolang/jeo/representation/Base64BytecodeTest.java b/src/test/java/org/eolang/jeo/representation/Base64BytecodeTest.java
new file mode 100644
index 000000000..f0e3b652f
--- /dev/null
+++ b/src/test/java/org/eolang/jeo/representation/Base64BytecodeTest.java
@@ -0,0 +1,46 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016-2023 Objectionary.com
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.eolang.jeo.representation;
+
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test case for {@link Base64Bytecode}.
+ *
+ * @since 0.1.0
+ */
+class Base64BytecodeTest {
+
+    @Test
+    void convertsToString() {
+        final byte[] bytes = {0x01, 0x02, 0x03};
+        MatcherAssert.assertThat(
+            "The string representation of the bytecode` is not correct",
+            new Base64Bytecode(bytes).asString(),
+            Matchers.equalTo("AQID")
+        );
+    }
+}