diff --git a/source/blender/compositor/realtime_compositor/shaders/compositor_plane_deform.glsl b/source/blender/compositor/realtime_compositor/shaders/compositor_plane_deform.glsl
index ced3b24691f..9444ee154de 100644
--- a/source/blender/compositor/realtime_compositor/shaders/compositor_plane_deform.glsl
+++ b/source/blender/compositor/realtime_compositor/shaders/compositor_plane_deform.glsl
@@ -7,17 +7,19 @@
 void main()
 {
   ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
+  vec2 input_size = vec2(texture_size(input_tx));
 
-  vec2 coordinates = (vec2(texel) + vec2(0.5)) / vec2(texture_size(input_tx));
+  vec2 coordinates = (vec2(texel) + vec2(0.5)) / input_size;
 
   vec3 transformed_coordinates = mat3(homography_matrix) * vec3(coordinates, 1.0);
   vec2 projected_coordinates = transformed_coordinates.xy / transformed_coordinates.z;
 
   /* The derivatives of the projected coordinates with respect to x and y are the first and
    * second columns respectively, divided by the z projection factor as can be shown by
-   * differentiating the above matrix multiplication with respect to x and y. */
-  vec2 x_gradient = homography_matrix[0].xy / transformed_coordinates.z;
-  vec2 y_gradient = homography_matrix[1].xy / transformed_coordinates.z;
+   * differentiating the above matrix multiplication with respect to x and y. Divide by the input
+   * size since textureGrad assumes derivatives with respect to texel coordinates. */
+  vec2 x_gradient = (homography_matrix[0].xy / transformed_coordinates.z) / input_size.x;
+  vec2 y_gradient = (homography_matrix[1].xy / transformed_coordinates.z) / input_size.y;
 
   vec4 sampled_color = textureGrad(input_tx, projected_coordinates, x_gradient, y_gradient);
 
diff --git a/source/blender/compositor/realtime_compositor/shaders/compositor_plane_deform_motion_blur.glsl b/source/blender/compositor/realtime_compositor/shaders/compositor_plane_deform_motion_blur.glsl
index e4981d6dacd..6ad6084225c 100644
--- a/source/blender/compositor/realtime_compositor/shaders/compositor_plane_deform_motion_blur.glsl
+++ b/source/blender/compositor/realtime_compositor/shaders/compositor_plane_deform_motion_blur.glsl
@@ -7,8 +7,9 @@
 void main()
 {
   ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
+  vec2 input_size = vec2(texture_size(input_tx));
 
-  vec2 coordinates = (vec2(texel) + vec2(0.5)) / vec2(imageSize(output_img));
+  vec2 coordinates = (vec2(texel) + vec2(0.5)) / input_size;
 
   vec4 accumulated_color = vec4(0.0);
   for (int i = 0; i < number_of_motion_blur_samples; i++) {
@@ -19,9 +20,10 @@ void main()
 
     /* The derivatives of the projected coordinates with respect to x and y are the first and
      * second columns respectively, divided by the z projection factor as can be shown by
-     * differentiating the above matrix multiplication with respect to x and y. */
-    vec2 x_gradient = homography_matrix[0].xy / transformed_coordinates.z;
-    vec2 y_gradient = homography_matrix[1].xy / transformed_coordinates.z;
+     * differentiating the above matrix multiplication with respect to x and y. Divide by the input
+     * size since textureGrad assumes derivatives with respect to texel coordinates. */
+    vec2 x_gradient = (homography_matrix[0].xy / transformed_coordinates.z) / input_size.x;
+    vec2 y_gradient = (homography_matrix[1].xy / transformed_coordinates.z) / input_size.y;
 
     vec4 sampled_color = textureGrad(input_tx, projected_coordinates, x_gradient, y_gradient);
     accumulated_color += sampled_color;