diff --git a/src/Classes/ShaderImageEffect.gd b/src/Classes/ShaderImageEffect.gd
index 2608d7ae2..04604fb0f 100644
--- a/src/Classes/ShaderImageEffect.gd
+++ b/src/Classes/ShaderImageEffect.gd
@@ -7,6 +7,16 @@ signal done
 
 func generate_image(img: Image, shader: Shader, params: Dictionary, size: Vector2i) -> void:
 	# duplicate shader before modifying code to avoid affecting original resource
+	var resized_width := false
+	var resized_height := false
+	if size.x == 1:
+		size.x = 2
+		img.crop(2, img.get_height())
+		resized_width = true
+	if size.y == 1:
+		size.y = 2
+		img.crop(img.get_width(), 2)
+		resized_height = true
 	shader = shader.duplicate()
 	shader.code = shader.code.replace("unshaded", "unshaded, blend_premul_alpha")
 	var vp := RenderingServer.viewport_create()
@@ -46,4 +56,8 @@ func generate_image(img: Image, shader: Shader, params: Dictionary, size: Vector
 	RenderingServer.free_rid(texture)
 	viewport_texture.convert(Image.FORMAT_RGBA8)
 	img.copy_from(viewport_texture)
+	if resized_width:
+		img.crop(img.get_width() - 1, img.get_height())
+	if resized_height:
+		img.crop(img.get_width(), img.get_height() - 1)
 	done.emit()