diff --git a/eo-runtime/src/test/java/EOorg/EOeolang/EOintTest.java b/eo-runtime/src/test/java/EOorg/EOeolang/EOintTest.java
index 375a92c025..14a2042419 100644
--- a/eo-runtime/src/test/java/EOorg/EOeolang/EOintTest.java
+++ b/eo-runtime/src/test/java/EOorg/EOeolang/EOintTest.java
@@ -26,3 +26,37 @@
  * @checkstyle PackageNameCheck (10 lines)
  */
 package EOorg.EOeolang;
+
+import org.eolang.Data;
+import org.eolang.Phi;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test case for {@link EOint}.
+ *
+ * @since 0.1
+ * @checkstyle TypeNameCheck (4 lines)
+ */
+public class EOintTest {
+
+    @Test
+    void hasEqualHashes() {
+        final Phi left = new Data.ToPhi(42L);
+        final Phi right = new Data.ToPhi(42L);
+        MatcherAssert.assertThat(
+            left.hashCode(),
+            Matchers.equalTo(right.hashCode())
+        );
+    }
+
+    @Test
+    void hasHashEvenWithoutData() {
+        final Phi phi = new EOint(Phi.Φ);
+        MatcherAssert.assertThat(
+            phi.hashCode(),
+            Matchers.greaterThan(0)
+        );
+    }
+}