diff --git a/cpp/src/arrow/testing/fixed_width_test_util.h b/cpp/src/arrow/testing/fixed_width_test_util.h
index 1eec5df4eb939..50be11758f469 100644
--- a/cpp/src/arrow/testing/fixed_width_test_util.h
+++ b/cpp/src/arrow/testing/fixed_width_test_util.h
@@ -20,10 +20,11 @@
 #include <vector>
 
 #include "arrow/builder.h"
+#include "arrow/testing/visibility.h"
 
 namespace arrow::util::internal {
 
-class NestedListGenerator {
+class ARROW_TESTING_EXPORT NestedListGenerator {
  public:
   /// \brief Create a nested FixedSizeListType.
   ///