diff --git a/spec-nylas/stores/draft-store-spec.coffee b/spec-nylas/stores/draft-store-spec.coffee
index 137cf8edf..e25fa9b3c 100644
--- a/spec-nylas/stores/draft-store-spec.coffee
+++ b/spec-nylas/stores/draft-store-spec.coffee
@@ -673,6 +673,22 @@ describe "DraftStore", ->
         DraftStore._onHandleMailtoLink('mailto:bengotow@gmail.com')
         expect(received.body.indexOf("Edited by TestExtension!")).toBe(0)
 
+    it "should be case-insensitive towards subject keys", ->
+      received = null
+      spyOn(DraftStore, '_finalizeAndPersistNewMessage').andCallFake (draft) ->
+        received = draft
+        Promise.resolve({draftLocalId: 123})
+
+      expected = "EmailSubjectLOLOL"
+      DraftStore._onHandleMailtoLink('mailto:asdf@asdf.com?subject=' + expected)
+      expect(received.subject).toBe(expected)
+
+      DraftStore._onHandleMailtoLink('mailto:asdf@asdf.com?Subject=' + expected)
+      expect(received.subject).toBe(expected)
+
+      DraftStore._onHandleMailtoLink('mailto:asdf@asdf.com?SUBJECT=' + expected)
+      expect(received.subject).toBe(expected)
+
     it "should correctly instantiate drafts for a wide range of mailto URLs", ->
       received = null
       spyOn(DatabaseStore, 'persistModel').andCallFake (draft) ->
diff --git a/src/flux/stores/draft-store.coffee b/src/flux/stores/draft-store.coffee
index 4a939f262..83bf476e0 100644
--- a/src/flux/stores/draft-store.coffee
+++ b/src/flux/stores/draft-store.coffee
@@ -365,6 +365,9 @@ class DraftStore
     query = require('querystring').parse(query)
     query.to = to
 
+    for key, val of query
+      query[key.toLowerCase()] = val
+
     draft = new Message
       body: query.body || ''
       subject: query.subject || '',