diff --git a/wp-admin/edit-form-advanced.php b/wp-admin/edit-form-advanced.php
index 887f31ad28..8dc481508f 100644
--- a/wp-admin/edit-form-advanced.php
+++ b/wp-admin/edit-form-advanced.php
@@ -24,9 +24,16 @@ $post_ID = isset($post_ID) ? (int) $post_ID : 0;
 $user_ID = isset($user_ID) ? (int) $user_ID : 0;
 $action = isset($action) ? $action : '';
 
-$media_support = theme_supports_thumbnails( $post ) || post_supports_thumbnails( $post );
+$thumbnail_support = current_theme_supports( 'post-thumbnails', $post_type ) && post_type_supports( $post_type, 'thumbnail' );
+if ( ! $thumbnail_support && 'attachment' === $post_type && $post->post_mime_type ) {
+	if ( 0 === strpos( $post->post_mime_type, 'audio/' ) ) {
+		$thumbnail_support = post_type_supports( 'attachment:audio', 'thumbnail' ) || current_theme_supports( 'post-thumbnails', 'attachment:audio' );
+	} elseif ( 0 === strpos( $post->post_mime_type, 'video/' ) ) {
+		$thumbnail_support = post_type_supports( 'attachment:video', 'thumbnail' ) || current_theme_supports( 'post-thumbnails', 'attachment:video' );
+	}
+}
 
-if ( post_type_supports( $post_type, 'editor' ) || post_type_supports( $post_type, 'thumbnail' ) || $media_support ) {
+if ( $thumbnail_support ) {
 	add_thickbox();
 	wp_enqueue_media( array( 'post' => $post_ID ) );
 }
@@ -169,7 +176,7 @@ foreach ( get_object_taxonomies( $post ) as $tax_name ) {
 if ( post_type_supports($post_type, 'page-attributes') )
 	add_meta_box('pageparentdiv', 'page' == $post_type ? __('Page Attributes') : __('Attributes'), 'page_attributes_meta_box', null, 'side', 'core');
 
-if ( current_theme_supports( 'post-thumbnails', $post_type ) || post_supports_thumbnails( $post ) )
+if ( $thumbnail_support )
 	add_meta_box('postimagediv', __('Featured Image'), 'post_thumbnail_meta_box', null, 'side', 'low');
 
 if ( post_type_supports($post_type, 'excerpt') )
diff --git a/wp-includes/media.php b/wp-includes/media.php
index 7feccd00c3..a92873062d 100644
--- a/wp-includes/media.php
+++ b/wp-includes/media.php
@@ -2452,7 +2452,16 @@ function wp_enqueue_media( $args = array() ) {
 			'nonce' => wp_create_nonce( 'update-post_' . $post->ID ),
 		);
 
-		if ( theme_supports_thumbnails( $post ) || post_supports_thumbnails( $post ) ) {
+		$thumbnail_support = current_theme_supports( 'post-thumbnails', $post->post_type ) && post_type_supports( $post->post_type, 'thumbnail' );
+		if ( ! $thumbnail_support && 'attachment' === $post->post_type && $post->post_mime_type ) {
+			if ( 0 === strpos( $post->post_mime_type, 'audio/' ) ) {
+				$thumbnail_support = post_type_supports( 'attachment:audio', 'thumbnail' ) || current_theme_supports( 'post-thumbnails', 'attachment:audio' );
+			} elseif ( 0 === strpos( $post->post_mime_type, 'video/' ) ) {
+				$thumbnail_support = post_type_supports( 'attachment:video', 'thumbnail' ) || current_theme_supports( 'post-thumbnails', 'attachment:video' );
+			}
+		}
+
+		if ( $thumbnail_support ) {
 			$featured_image_id = get_post_meta( $post->ID, '_thumbnail_id', true );
 			$settings['post']['featuredImageId'] = $featured_image_id ? $featured_image_id : -1;
 		}
@@ -2756,45 +2765,3 @@ function wp_maybe_generate_attachment_metadata( $attachment ) {
 		}
 	}
 }
-
-/**
- * Determine if a post supports thumbnails based on the passed post object.
- *
- * @since 3.9.0
- *
- * @param WP_Post $post Post object.
- *
- * @return bool Whether the post type supports thumbnails.
- */
-function post_supports_thumbnails( $post ) {
-	if ( 'attachment' === $post->post_type ) {
-		if ( 0 === strpos( $post->post_mime_type, 'audio' ) ) {
-			return post_type_supports( 'attachment:audio', 'thumbnail' );
-		} elseif ( 0 === strpos( $post->post_mime_type, 'video' ) ) {
-			return post_type_supports( 'attachment:video', 'thumbnail' );
-		}
-	}
-
-	return post_type_supports( $post->post_type, 'thumbnail' );
-}
-
-/**
- * Determine if a theme supports thumbnails based on the passed post object.
- *
- * @since 3.9.0
- *
- * @param WP_Post $post Post object.
- *
- * @return bool Whether the current theme supports thumbnails.
- */
-function theme_supports_thumbnails( $post ) {
-	if ( 'attachment' === $post->post_type ) {
-		if ( 0 === strpos( $post->post_mime_type, 'audio' ) ) {
-			return current_theme_supports( 'post-thumbnails', 'attachment:audio' );
-		} elseif ( 0 === strpos( $post->post_mime_type, 'video' ) ) {
-			return current_theme_supports( 'post-thumbnails', 'attachment:video' );
-		}
-	}
-
-	return current_theme_supports( 'post-thumbnails', $post->post_type );
-}