diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/UnphiMojoCacheTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/UnphiMojoCacheTest.java
new file mode 100644
index 0000000000..8e0cd2a00c
--- /dev/null
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/UnphiMojoCacheTest.java
@@ -0,0 +1,100 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016-2024 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.maven;
+
+import com.yegor256.Mktmp;
+import com.yegor256.MktmpResolver;
+import java.io.File;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.eolang.maven.util.HmBase;
+import org.eolang.maven.util.Home;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junitpioneer.jupiter.ExpectedToFail;
+
+/**
+ * Test cases for caching in {@link UnphiMojo}.
+ * @since 0.50.0
+ */
+@ExtendWith(MktmpResolver.class)
+@SuppressWarnings("JTCOP.RuleAllTestsHaveProductionClass")
+final class UnphiMojoCacheTest {
+
+    @Test
+    @ExpectedToFail
+    void touchesCacheNot(@Mktmp final Path temp) throws Exception {
+        final Home workspace = new HmBase(temp);
+        workspace.save(
+            "{⟦std ↦ Φ.org.eolang.io.stdout, y ↦ Φ.org.eolang.x⟧}",
+            Paths.get("target/eo/phi/std.phi")
+        );
+        workspace.save(
+            "some valid XMIR",
+            Paths.get("target/eo/1-parse/std.xmir")
+        );
+        final File xmir = temp.resolve("target/1-parse/std.xmir").toFile();
+        final long modified = xmir.lastModified();
+        new FakeMaven(temp).execute(UnphiMojo.class);
+        MatcherAssert.assertThat(
+            String.format(
+                "There should be file with .%s extension after parsing phi to XMIR, but there isn't",
+                AssembleMojo.XMIR
+            ),
+            modified,
+            Matchers.equalTo(xmir.lastModified())
+        );
+    }
+
+    @Test
+    void touchesInvalidCache(@Mktmp final Path temp) throws Exception {
+        final Home workspace = new HmBase(temp);
+        workspace.save(
+            "some valid XMIR",
+            Paths.get("target/eo/1-parse/std.xmir")
+        );
+        workspace.save(
+            "{⟦std ↦ Φ.org.eolang.io.stdout, y ↦ Φ.org.eolang.x⟧}",
+            Paths.get("target/eo/phi/std.phi")
+        );
+        final File xmir = temp.resolve("target/1-parse/std.xmir").toFile();
+        final long modified = xmir.lastModified();
+        final FakeMaven mvn = new FakeMaven(temp).execute(UnphiMojo.class);
+        workspace.save(
+            "some valid XMIR",
+            Paths.get("target/1-parse/std.xmir")
+        );
+        mvn.execute(UnphiMojo.class);
+        MatcherAssert.assertThat(
+            String.format(
+                "There should be file with .%s extension after parsing phi to XMIR, but there isn't",
+                AssembleMojo.XMIR
+            ),
+            modified,
+            Matchers.lessThan(xmir.lastModified())
+        );
+    }
+}