diff --git a/apps/converter/backends/python/base.py b/apps/converter/backends/python/base.py
index 3e0f8cd84f..a57e1f0d2a 100644
--- a/apps/converter/backends/python/base.py
+++ b/apps/converter/backends/python/base.py
@@ -25,7 +25,7 @@ class ConverterClass(ConverterBase):
     def get_page_count(self, input_filepath):
         page_count = 1
 
-        mimetype, encoding = get_mimetype(input_filepath)
+        mimetype, encoding = get_mimetype(open(input_filepath, 'rb'), input_filepath)
         if mimetype == 'application/pdf':
             # If file is a PDF open it with slate to determine the page
             # count
@@ -50,7 +50,7 @@ class ConverterClass(ConverterBase):
 
     def convert_file(self, input_filepath, output_filepath, transformations=None, page=DEFAULT_PAGE_NUMBER, file_format=DEFAULT_FILE_FORMAT):
         tmpfile = None
-        mimetype, encoding = get_mimetype(input_filepath)
+        mimetype, encoding = get_mimetype(open(input_filepath, 'rb'), input_filepath)
         if mimetype == 'application/pdf' and USE_GHOSTSCRIPT:
             # If file is a PDF open it with ghostscript and convert it to
             # TIFF
diff --git a/apps/documents/models.py b/apps/documents/models.py
index 1d4b67881f..efdd6a6841 100644
--- a/apps/documents/models.py
+++ b/apps/documents/models.py
@@ -17,7 +17,7 @@ from converter.api import get_page_count
 from converter.api import get_available_transformations_choices
 from converter.api import convert
 from converter.exceptions import UnknownFileFormat, UnkownConvertError
-from mimetype.api import get_document_mimetype, get_icon_file_path, \
+from mimetype.api import get_mimetype, get_icon_file_path, \
     get_error_icon_file_path
 
 from documents.conf.settings import CHECKSUM_FUNCTION
@@ -135,7 +135,7 @@ class Document(models.Model):
         """
         if self.exists():
             try:
-                self.file_mimetype, self.mime_encoding = get_document_mimetype(self)
+                self.file_mimetype, self.mime_encoding = get_mimetype(self.open(), self.get_fullname())
             except:
                 self.file_mimetype = u''
                 self.file_mime_encoding = u''
diff --git a/apps/mimetype/api.py b/apps/mimetype/api.py
index 3ef46c711d..3390e5995f 100644
--- a/apps/mimetype/api.py
+++ b/apps/mimetype/api.py
@@ -82,9 +82,9 @@ def get_error_icon_file_path():
         return os.path.join(settings.PROJECT_ROOT, 'apps', 'mimetype', 'static', MIMETYPE_ICONS_DIRECTORY_NAME, ERROR_FILE_NAME)
     else:
         return os.path.join(settings.STATIC_ROOT, MIMETYPE_ICONS_DIRECTORY_NAME, ERROR_FILE_NAME)
-   
 
-def get_mimetype(filepath):
+   
+def get_mimetype(file_description, filepath):
     """
     Determine a file's mimetype by calling the system's libmagic
     library via python-magic or fallback to use python's mimetypes
@@ -92,50 +92,16 @@ def get_mimetype(filepath):
     """
     file_mimetype = u''
     file_mime_encoding = u''
-    source = None
     if USE_PYTHON_MAGIC:
-        if os.path.exists(filepath):
-            try:
-                source = open(filepath, 'rb')
-                mime = magic.Magic(mime=True)
-                file_mimetype = mime.from_buffer(source.read())
-                source.seek(0)
-                mime_encoding = magic.Magic(mime_encoding=True)
-                file_mime_encoding = mime_encoding.from_buffer(source.read())
-            finally:
-                if source:
-                    source.close()
+        mime = magic.Magic(mime=True)
+        file_mimetype = mime.from_buffer(file_description.read())
+        file_description.seek(0)
+        mime_encoding = magic.Magic(mime_encoding=True)
+        file_mime_encoding = mime_encoding.from_buffer(file_description.read())
     else:
         path, filename = os.path.split(filepath)
         file_mimetype, file_mime_encoding = mimetypes.guess_type(filename)
 
-    return file_mimetype, file_mime_encoding
-
-
-def get_document_mimetype(document):
-    """
-    Determine a documents mimetype by calling the system's libmagic
-    library via python-magic or fallback to use python's mimetypes
-    library
-    """
-    file_mimetype = u''
-    file_mime_encoding = u''
-
-    source = None
-
-    if USE_PYTHON_MAGIC:
-        if document.exists():
-            try:
-                source = document.open()
-                mime = magic.Magic(mime=True)
-                file_mimetype = mime.from_buffer(source.read())
-                source.seek(0)
-                mime_encoding = magic.Magic(mime_encoding=True)
-                file_mime_encoding = mime_encoding.from_buffer(source.read())
-            finally:
-                if source:
-                    source.close()
-    else:
-        file_mimetype, file_mime_encoding = mimetypes.guess_type(document.get_fullname())
+    file_description.close()
 
     return file_mimetype, file_mime_encoding
diff --git a/apps/sources/staging.py b/apps/sources/staging.py
index 8a0a200859..b2edd41848 100644
--- a/apps/sources/staging.py
+++ b/apps/sources/staging.py
@@ -138,6 +138,7 @@ class StagingFile(object):
         try:
             return convert(self.filepath, size=size, cleanup_files=False, transformations=transformations)
         except UnknownFileFormat:
-            return get_icon_file_path(get_mimetype(self.filepath))
+            mimetype, encoding = get_mimetype(open(self.filepath, 'rb'), self.filepath)
+            return get_icon_file_path(mimetype)
         except UnkownConvertError:
             return get_error_icon_file_path()