diff --git a/rest_framework/compat.py b/rest_framework/compat.py
index 9422e6ad5..3e1706b6a 100644
--- a/rest_framework/compat.py
+++ b/rest_framework/compat.py
@@ -184,10 +184,12 @@ if 'patch' not in View.http_method_names:
 try:
     import markdown
 
-    if markdown.version <= '2.2':
+    if not hasattr(markdown, '__version__') and markdown.version <= '2.2':
         HEADERID_EXT_PATH = 'headerid'
         LEVEL_PARAM = 'level'
-    elif markdown.version < '2.6':
+    elif not hasattr(markdown, '__version__') or (
+                type(markdown.__version__) != type('') and markdown.version < '2.6'
+            ):
         HEADERID_EXT_PATH = 'markdown.extensions.headerid'
         LEVEL_PARAM = 'level'
     else: