diff --git a/lib/src/controllers.dart b/lib/src/controllers.dart
index ad095e3..455a7d5 100644
--- a/lib/src/controllers.dart
+++ b/lib/src/controllers.dart
@@ -15,7 +15,9 @@ class RangePickerController {
       this.minimumDateRangeLength,
       this.maximumDateRangeLength,
       this.disabledDates = const [],
-      this.allowSingleTapDaySelection = false}) {
+      this.allowSingleTapDaySelection = false,
+      this.allowBackwardsDaySelection = true})
+      : origMinDate = minDate {
     if (dateRange != null) {
       startDate = dateRange.start;
       endDate = dateRange.end;
@@ -29,11 +31,16 @@ class RangePickerController {
 
   final bool allowSingleTapDaySelection;
 
+  /// Whether the user can select a date range backwards (i.e. start date is after end date).
+  final bool allowBackwardsDaySelection;
+
   final ValueChanged<DateRange?> onDateRangeChanged;
 
   /// The minimum date that can be selected. (inclusive)
   DateTime? minDate;
 
+  final DateTime? origMinDate;
+
   /// The maximum date that can be selected. (inclusive)
   DateTime? maxDate;
 
@@ -84,6 +91,9 @@ class RangePickerController {
         onDateRangeChanged(DateRange(startDate!, startDate!));
       }
     }
+    if (!allowBackwardsDaySelection) {
+      minDate = startDate != null && endDate == null ? startDate : origMinDate;
+    }
   }
 
   /// Returns whether the [date] is in the selected range or not.
diff --git a/lib/src/widgets/date_range_picker.dart b/lib/src/widgets/date_range_picker.dart
index ccba617..101e6d6 100644
--- a/lib/src/widgets/date_range_picker.dart
+++ b/lib/src/widgets/date_range_picker.dart
@@ -151,6 +151,7 @@ class DateRangePickerWidget extends StatefulWidget {
     this.displayMonthsSeparator = true,
     this.separatorThickness = 1,
     this.allowSingleTapDaySelection = false,
+    this.allowBackwardsDaySelection = true,
     this.firstDayOfWeek = 0,
     this.lengthOfDateName = 3,
   })  : assert(
@@ -197,6 +198,10 @@ class DateRangePickerWidget extends StatefulWidget {
   /// day twice).
   final bool allowSingleTapDaySelection;
 
+  /// Set [allowBackwardsDaySelection] to false to prevent the user from selecting
+  /// a date range backwards (i.e. start date is after end date).
+  final bool allowBackwardsDaySelection;
+
   /// The theme used to customize the appearance of the picker.
   final CalendarTheme theme;
 
@@ -226,6 +231,7 @@ class DateRangePickerWidgetState extends State<DateRangePickerWidget> {
     minimumDateRangeLength: widget.minimumDateRangeLength,
     maximumDateRangeLength: widget.maximumDateRangeLength,
     allowSingleTapDaySelection: widget.allowSingleTapDaySelection,
+    allowBackwardsDaySelection: widget.allowBackwardsDaySelection,
   );
 
   late final calendarController = CalendarWidgetController(