diff --git a/cms/djangoapps/contentstore/tests/test_assets.py b/cms/djangoapps/contentstore/tests/test_assets.py
index 9ed9650b45eb..f9e2a65e1de9 100644
--- a/cms/djangoapps/contentstore/tests/test_assets.py
+++ b/cms/djangoapps/contentstore/tests/test_assets.py
@@ -61,6 +61,14 @@ def test_toy_assets(self):
         self.assertContains(resp, "new AssetCollection([{")
         self.assertContains(resp, "/c4x/edX/toy/asset/handouts_sample_handout.txt")
 
+        # Test valid contentType for pdf asset (textbook.pdf)
+        self.assertContains(resp, "/c4x/edX/toy/asset/textbook.pdf")
+        asset_location = StaticContent.get_location_from_path('/c4x/edX/toy/asset/textbook.pdf')
+        content = contentstore().find(asset_location)
+        # Check after import textbook.pdf has valid contentType ('application/pdf')
+        # Note: Actual contentType for textbook.pdf in asset.json is 'text/pdf'
+        self.assertEqual(content.content_type, 'application/pdf')
+
 
 class UploadTestCase(CourseTestCase):
     """
diff --git a/common/lib/xmodule/xmodule/modulestore/xml_importer.py b/common/lib/xmodule/xmodule/modulestore/xml_importer.py
index 64392b764395..744a771e1a43 100644
--- a/common/lib/xmodule/xmodule/modulestore/xml_importer.py
+++ b/common/lib/xmodule/xmodule/modulestore/xml_importer.py
@@ -33,6 +33,7 @@ def import_static_content(
         policy = {}
 
     verbose = True
+    mimetypes_list = mimetypes.types_map.values()
 
     for dirname, _, filenames in os.walk(static_dir):
         for filename in filenames:
@@ -64,10 +65,11 @@ def import_static_content(
             policy_ele = policy.get(content_loc.name, {})
             displayname = policy_ele.get('displayname', filename)
             locked = policy_ele.get('locked', False)
-            mime_type = policy_ele.get(
-                'contentType',
-                mimetypes.guess_type(filename)[0]
-            )
+            mime_type = policy_ele.get('contentType')
+
+            # Check extracted contentType in list of all valid mimetypes
+            if not mime_type or mime_type not in mimetypes_list:
+                mime_type = mimetypes.guess_type(filename)[0]   # Assign guessed mimetype
             content = StaticContent(
                 content_loc, displayname, mime_type, data,
                 import_path=fullname_with_subpath, locked=locked
diff --git a/common/test/data/toy/policies/assets.json b/common/test/data/toy/policies/assets.json
new file mode 100644
index 000000000000..c051b44f8145
--- /dev/null
+++ b/common/test/data/toy/policies/assets.json
@@ -0,0 +1,10 @@
+{
+    "textbook.pdf":{
+        "contentType":"text/pdf",
+        "displayname":"textbook.pdf",
+        "locked":false,
+        "filename":"/c4x/edx/toy/asset/textbook.pdf",
+        "import_path":null,
+        "thumbnail_location":null
+    }
+}
diff --git a/common/test/data/toy/static/textbook.pdf b/common/test/data/toy/static/textbook.pdf
new file mode 100644
index 000000000000..e6e7a031ce59
Binary files /dev/null and b/common/test/data/toy/static/textbook.pdf differ