diff --git a/isthmus/src/test/java/io/substrait/isthmus/ExpressionRoundtripTest.java b/isthmus/src/test/java/io/substrait/isthmus/ExpressionRoundtripTest.java
new file mode 100644
index 00000000..a00d5d31
--- /dev/null
+++ b/isthmus/src/test/java/io/substrait/isthmus/ExpressionRoundtripTest.java
@@ -0,0 +1,72 @@
+package io.substrait.isthmus;
+
+import static io.substrait.isthmus.expression.CallConverters.CREATE_SEARCH_CONV;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import io.substrait.dsl.SubstraitBuilder;
+import io.substrait.expression.proto.ExpressionProtoConverter;
+import io.substrait.extension.ExtensionCollector;
+import io.substrait.extension.SimpleExtension;
+import io.substrait.isthmus.expression.RexExpressionConverter;
+import io.substrait.isthmus.expression.ScalarFunctionConverter;
+import io.substrait.plan.Plan;
+import io.substrait.relation.Rel;
+import io.substrait.type.Type;
+import io.substrait.type.TypeCreator;
+import java.io.IOException;
+import java.util.List;
+import org.apache.calcite.rel.core.Filter;
+import org.junit.jupiter.api.Test;
+
+/** Tests which test that an expression round-trips correctly to and from Calcite expressions. */
+public class ExpressionRoundtripTest extends PlanTestBase {
+  static final TypeCreator R = TypeCreator.of(false);
+  static final TypeCreator N = TypeCreator.of(true);
+
+  final SubstraitBuilder b = new SubstraitBuilder(extensions);
+
+  // Define a shared table (i.e. a NamedScan) for use in tests.
+  final List<Type> commonTableType = List.of(R.I32, R.FP32, N.STRING, N.BOOLEAN);
+  final Rel commonTable =
+      b.namedScan(List.of("example"), List.of("a", "b", "c", "d"), commonTableType);
+
+  final SubstraitToCalcite converter = new SubstraitToCalcite(extensions, typeFactory);
+
+  @Test
+  public void singleOrList() throws IOException {
+    Plan.Root root =
+        b.root(
+            b.filter(
+                input -> b.singleOrList(b.fieldReference(input, 0), b.i32(5), b.i32(10)),
+                commonTable));
+    var relNode = converter.convert(root.getInput());
+    var expression =
+        ((Filter) relNode)
+            .getCondition()
+            .accept(
+                new RexExpressionConverter(
+                    CREATE_SEARCH_CONV.apply(relNode.getCluster().getRexBuilder()),
+                    new ScalarFunctionConverter(
+                        SimpleExtension.loadDefaults().scalarFunctions(), typeFactory)));
+    var to = new ExpressionProtoConverter(new ExtensionCollector(), null);
+    assertEquals(
+        expression.accept(to),
+        b.scalarFn(
+                "/functions_boolean.yaml",
+                "or:bool",
+                R.BOOLEAN,
+                b.scalarFn(
+                    "/functions_comparison.yaml",
+                    "equal:any_any",
+                    R.BOOLEAN,
+                    b.fieldReference(commonTable, 0),
+                    b.i32(5)),
+                b.scalarFn(
+                    "/functions_comparison.yaml",
+                    "equal:any_any",
+                    R.BOOLEAN,
+                    b.fieldReference(commonTable, 0),
+                    b.i32(10)))
+            .accept(to));
+  }
+}
diff --git a/isthmus/src/test/java/io/substrait/isthmus/SubstraitRelNodeConverterTest.java b/isthmus/src/test/java/io/substrait/isthmus/SubstraitRelNodeConverterTest.java
index 3aa307cf..1c90c0be 100644
--- a/isthmus/src/test/java/io/substrait/isthmus/SubstraitRelNodeConverterTest.java
+++ b/isthmus/src/test/java/io/substrait/isthmus/SubstraitRelNodeConverterTest.java
@@ -131,17 +131,6 @@ public void emit() {
       var relNode = converter.convert(root.getInput());
       assertRowMatch(relNode.getRowType(), R.I32, N.STRING);
     }
-
-    @Test
-    public void singleOrList() {
-      Plan.Root root =
-          b.root(
-              b.filter(
-                  input -> b.singleOrList(b.fieldReference(input, 0), b.i32(5), b.i32(10)),
-                  commonTable));
-      var relNode = converter.convert(root.getInput());
-      assertRowMatch(relNode.getRowType(), commonTableType);
-    }
   }
 
   @Nested