diff --git a/public/js/crop_editor.js b/public/js/crop_editor.js
index cc005993..555ec832 100644
--- a/public/js/crop_editor.js
+++ b/public/js/crop_editor.js
@@ -292,10 +292,23 @@ class CropEditor {
 			let targetAspectRatio = current.crop_width / current.crop_height;
 
 			if (Math.abs(currentAspectRatio - targetAspectRatio) > 0.001) {
+				// Landscape?
 				if (targetAspectRatio > 1.0) {
-					this.crop_height.value = Math.ceil(this.crop_width.value / targetAspectRatio);
-				} else {
-					this.crop_width.value = Math.ceil(this.crop_height.value * targetAspectRatio);
+					let height = Math.ceil(this.crop_width.value / targetAspectRatio);
+					if (parseInt(this.source_y.value) + height > this.original_image.naturalHeight) {
+						height = this.original_image.naturalHeight - this.source_y.value;
+					}
+					this.crop_width.value = height * targetAspectRatio;
+					this.crop_height.value = height;
+				}
+				// Portrait?
+				else {
+					let width = Math.ceil(this.crop_height.value * targetAspectRatio);
+					if (parseInt(this.source_x.value) + width > this.original_image.naturalWidth) {
+						width = this.original_image.naturalWidth - this.source_x.value;
+					}
+					this.crop_width.value = width;
+					this.crop_height.value = width / targetAspectRatio;
 				}
 			}
 		}