diff --git a/src/Assets/Asset.php b/src/Assets/Asset.php
index 060590b8d34..05e7336c130 100644
--- a/src/Assets/Asset.php
+++ b/src/Assets/Asset.php
@@ -10,7 +10,6 @@
 use Statamic\Contracts\Data\Augmentable;
 use Statamic\Contracts\Data\Augmented;
 use Statamic\Data\ContainsData;
-use Statamic\Data\Data;
 use Statamic\Data\HasAugmentedInstance;
 use Statamic\Events\AssetDeleted;
 use Statamic\Events\AssetSaved;
@@ -713,6 +712,16 @@ public function extensionIsOneOf($filetypes = [])
         return in_array(strtolower($this->extension()), $filetypes);
     }
 
+    /**
+     * Check if asset's guessed file extension is one of a given list.
+     *
+     * @return string
+     */
+    public function guessedExtensionIsOneOf($filetypes = [])
+    {
+        return in_array(strtolower($this->guessedExtension()), $filetypes);
+    }
+
     public function __toString()
     {
         return $this->url() ?? $this->id();
diff --git a/src/Fieldtypes/Assets/Assets.php b/src/Fieldtypes/Assets/Assets.php
index 7188161fa7a..f812987ef17 100644
--- a/src/Fieldtypes/Assets/Assets.php
+++ b/src/Fieldtypes/Assets/Assets.php
@@ -173,17 +173,20 @@ public function fieldRules()
     {
         return collect(parent::fieldRules())->map(function ($rule) {
             $name = Str::before($rule, ':');
+            $parameters = explode(',', Str::after($rule, ':'));
 
             if ($name === 'image') {
                 return new ImageRule();
             }
 
             if ($name === 'mimes') {
-                $parameters = explode(',', Str::after($rule, ':'));
-
                 return new MimesRule($parameters);
             }
 
+            if ($name === 'mimetypes') {
+                return new MimetypesRule($parameters);
+            }
+
             return $rule;
         })->all();
     }
diff --git a/src/Fieldtypes/Assets/ImageRule.php b/src/Fieldtypes/Assets/ImageRule.php
index 97919cca0ff..ba3f6fb6e36 100644
--- a/src/Fieldtypes/Assets/ImageRule.php
+++ b/src/Fieldtypes/Assets/ImageRule.php
@@ -24,16 +24,18 @@ public function __construct($parameters = null)
      */
     public function passes($attribute, $value)
     {
-        return collect($value)->every(function ($id) {
+        $extensions = ['jpg', 'jpeg', 'png', 'gif', 'bmp', 'svg', 'webp'];
+
+        return collect($value)->every(function ($id) use ($extensions) {
             if ($id instanceof UploadedFile) {
-                return in_array($id->guessExtension(), ['jpg', 'jpeg', 'png', 'gif', 'webp']);
+                return in_array($id->guessExtension(), $extensions);
             }
 
             if (! $asset = Asset::find($id)) {
                 return false;
             }
 
-            return $asset->isImage();
+            return $asset->guessedExtensionIsOneOf($extensions);
         });
     }
 
diff --git a/src/Fieldtypes/Assets/MimesRule.php b/src/Fieldtypes/Assets/MimesRule.php
index 1196472e111..441fe7d8c7e 100644
--- a/src/Fieldtypes/Assets/MimesRule.php
+++ b/src/Fieldtypes/Assets/MimesRule.php
@@ -37,7 +37,7 @@ public function passes($attribute, $value)
                 return false;
             }
 
-            return $asset->extensionIsOneOf($this->parameters);
+            return $asset->guessedExtensionIsOneOf($this->parameters);
         });
     }
 
diff --git a/src/Fieldtypes/Assets/MimetypesRule.php b/src/Fieldtypes/Assets/MimetypesRule.php
new file mode 100644
index 00000000000..d74cb00e174
--- /dev/null
+++ b/src/Fieldtypes/Assets/MimetypesRule.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace Statamic\Fieldtypes\Assets;
+
+use Illuminate\Contracts\Validation\Rule;
+use Statamic\Facades\Asset;
+use Symfony\Component\HttpFoundation\File\UploadedFile;
+
+class MimetypesRule implements Rule
+{
+    protected $parameters;
+
+    public function __construct($parameters)
+    {
+        $this->parameters = $parameters;
+    }
+
+    /**
+     * Determine if the validation rule passes.
+     *
+     * @param  string  $attribute
+     * @param  mixed  $value
+     * @return bool
+     */
+    public function passes($attribute, $value)
+    {
+        return collect($value)->every(function ($id) {
+            if ($id instanceof UploadedFile) {
+                $mimeType = $id->getMimeType();
+            } elseif (! ($mimeType = optional(Asset::find($id))->mimeType())) {
+                return false;
+            }
+
+            return in_array($mimeType, $this->parameters) ||
+                in_array(explode('/', $mimeType)[0].'/*', $this->parameters);
+        });
+    }
+
+    /**
+     * Get the validation error message.
+     *
+     * @return string
+     */
+    public function message()
+    {
+        return str_replace(':values', join(', ', $this->parameters), __('statamic::validation.mimetypes'));
+    }
+}