@@ -23,7 +23,6 @@
 import org.apache.spark.sql.types.FloatType;
 import org.apache.spark.sql.types.IntegerType;
 import org.apache.spark.sql.types.LongType;
-import org.apache.spark.sql.types.MapType;
 import org.apache.spark.sql.types.ShortType;
 import org.apache.spark.sql.types.StringType;
 import org.apache.spark.sql.types.StructField;
@@ -125,9 +124,6 @@ private static ArrowType convertType(DataType sparkType) {
             return new ArrowType.List();
         } else if (sparkType instanceof StructType) {
             return new ArrowType.Struct();
-        } else if (sparkType instanceof MapType) {
-            // Map is represented as List<Struct<key, value>> in Arrow
-            return new ArrowType.List();
         } else {
             throw new UnsupportedOperationException("Unsupported Spark type for Arrow conversion: "
                     + sparkType.getClass().getName());
 
@@ -173,4 +173,14 @@ void unsupportedTypeIsRejected() {
                 assertThrows(UnsupportedOperationException.class, () -> SparkToArrowSchema.convert(schema));
         assertTrue(e.getMessage().contains("CalendarIntervalType"));
     }
+
+    @Test
+    @DisplayName("MapType is rejected rather than converted to a childless List")
+    void mapTypeIsRejected() {
+        StructType schema =
+                new StructType().add("m", DataTypes.createMapType(DataTypes.StringType, DataTypes.IntegerType));
+        UnsupportedOperationException e =
+                assertThrows(UnsupportedOperationException.class, () -> SparkToArrowSchema.convert(schema));
+        assertTrue(e.getMessage().contains("MapType"));
+    }
 }