diff --git a/dsl/jpql/src/test/kotlin/com/linecorp/kotlinjdsl/dsl/jpql/expression/LowerDslTest.kt b/dsl/jpql/src/test/kotlin/com/linecorp/kotlinjdsl/dsl/jpql/expression/LowerDslTest.kt
new file mode 100644
index 000000000..bc45c2eac
--- /dev/null
+++ b/dsl/jpql/src/test/kotlin/com/linecorp/kotlinjdsl/dsl/jpql/expression/LowerDslTest.kt
@@ -0,0 +1,47 @@
+package com.linecorp.kotlinjdsl.dsl.jpql.expression
+
+import com.linecorp.kotlinjdsl.dsl.jpql.queryPart
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.Expression
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.Expressions
+import org.assertj.core.api.WithAssertions
+import org.junit.jupiter.api.Test
+
+class LowerDslTest : WithAssertions {
+    private val string1 = "string1"
+
+    private val stringExpression1 = Expressions.value("string1")
+
+    @Test
+    fun `lower() with a string`() {
+        // when
+        val expression = queryPart {
+            lower(string1)
+        }.toExpression()
+
+        val actual: Expression<String> = expression // for type check
+
+        // then
+        val expected = Expressions.lower(
+            Expressions.value(string1),
+        )
+
+        assertThat(actual).isEqualTo(expected)
+    }
+
+    @Test
+    fun `lower() with a string expression`() {
+        // when
+        val expression = queryPart {
+            lower(stringExpression1)
+        }.toExpression()
+
+        val actual: Expression<String> = expression // for type check
+
+        // then
+        val expected = Expressions.lower(
+            stringExpression1,
+        )
+
+        assertThat(actual).isEqualTo(expected)
+    }
+}