diff --git a/CHANGES b/CHANGES
index a7d7d0f..38203c2 100644
--- a/CHANGES
+++ b/CHANGES
@@ -11,6 +11,8 @@
    to fail  (LP: #1842250)
  - Fix message extraction so that signing in the same pass through the milter
    as verifying works correctly
+ - Add debug logging for content type to assist troubleshooting MIME
+   conversion issues
 
 1.1.0 2019-04-12
  - Add SubDomains option to enable signing for sub-domains (LP: #1811535)
diff --git a/dkimpy_milter/__init__.py b/dkimpy_milter/__init__.py
index 68ece2e..89cc587 100644
--- a/dkimpy_milter/__init__.py
+++ b/dkimpy_milter/__init__.py
@@ -126,6 +126,11 @@ class dkimMilter(Milter.Base):
     @Milter.noreply
     def header(self, name, val):
         lname = name.lower()
+        if milterconfig.get('Syslog') and milterconfig.get('debugLevel') >= 4:
+            if lname == 'content-transfer-encoding':
+                syslog.syslog("content-transfer-encodeing: {0}".format(val))
+            if lname == 'content-type':
+                syslog.syslog("content-type: {0}".format(val))
         if lname == 'dkim-signature':
             if (milterconfig.get('Syslog') and
                     milterconfig.get('debugLevel') >= 1):