diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/BaseSummary.java b/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/BaseSummary.java
new file mode 100644
index 0000000000..4a59230144
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/BaseSummary.java
@@ -0,0 +1,62 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.metamodel.hhh18868;
+
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.MappedSuperclass;
+
+import java.io.Serializable;
+import java.math.BigDecimal;
+import java.util.Objects;
+
+@IdClass(PKey.class)
+@MappedSuperclass
+public class BaseSummary implements Serializable {
+
+	@Id
+	private Integer year;
+	@Id
+	private Integer month;
+	private BigDecimal value;
+
+	public Integer getYear() {
+		return year;
+	}
+
+	public void setYear(Integer year) {
+		this.year = year;
+	}
+
+	public Integer getMonth() {
+		return month;
+	}
+
+	public void setMonth(Integer month) {
+		this.month = month;
+	}
+
+	public BigDecimal getValue() {
+		return value;
+	}
+
+	public void setValue(BigDecimal value) {
+		this.value = value;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if ( o == null || getClass() != o.getClass() ) {
+			return false;
+		}
+		BaseSummary that = (BaseSummary) o;
+		return Objects.equals( year, that.year ) && Objects.equals( month, that.month );
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash( year, month );
+	}
+}
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/HHH18868Test.java b/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/HHH18868Test.java
new file mode 100644
index 0000000000..b06c6e4113
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/HHH18868Test.java
@@ -0,0 +1,34 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.metamodel.hhh18868;
+
+import jakarta.persistence.metamodel.SingularAttribute;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.JiraKey;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.Test;
+
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DomainModel(annotatedClasses = {Summary.class, BaseSummary.class})
+@SessionFactory
+@JiraKey( "HHH-18858" )
+public class HHH18868Test {
+
+	@Test
+	public void test(SessionFactoryScope scope) {
+		scope.inSession( entityManager -> {
+			final var yearAttribute = Summary_.year.getDeclaringType().getAttribute( "year" );
+			assertThat( yearAttribute ).isEqualTo( Summary_.year );
+			assertThat( ((SingularAttribute<?, ?>) yearAttribute).isId() ).isTrue();
+
+			final var monthAttribute = Summary_.month.getDeclaringType().getAttribute( "month" );
+			assertThat( monthAttribute ).isEqualTo( Summary_.month );
+			assertThat( ((SingularAttribute<?, ?>) monthAttribute).isId() ).isTrue();
+		} );
+	}
+}
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/PKey.java b/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/PKey.java
new file mode 100644
index 0000000000..be8bb7123d
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/PKey.java
@@ -0,0 +1,44 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.metamodel.hhh18868;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+public class PKey implements Serializable {
+
+	private Integer year;
+	private Integer month;
+
+	public Integer getYear() {
+		return year;
+	}
+
+	public void setYear(Integer year) {
+		this.year = year;
+	}
+
+	public Integer getMonth() {
+		return month;
+	}
+
+	public void setMonth(Integer month) {
+		this.month = month;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if ( o == null || getClass() != o.getClass() ) {
+			return false;
+		}
+		PKey pKey = (PKey) o;
+		return Objects.equals( year, pKey.year ) && Objects.equals( month, pKey.month );
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash( year, month );
+	}
+}
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/Summary.java b/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/Summary.java
new file mode 100644
index 0000000000..ef0d0849d4
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/metamodel/hhh18868/Summary.java
@@ -0,0 +1,11 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.metamodel.hhh18868;
+
+import jakarta.persistence.Entity;
+
+@Entity
+public class Summary extends BaseSummary {
+}