diff --git a/Text/Markdown.hs b/Text/Markdown.hs
--- a/Text/Markdown.hs
+++ b/Text/Markdown.hs
@@ -11,6 +11,7 @@
     , msFencedHandlers
     , msBlockCodeRenderer
     , msLinkNewTab
+    , msBlankBeforeBlockquote
       -- * Newtype
     , Markdown (..)
       -- * Fenced handlers
diff --git a/Text/Markdown/Block.hs b/Text/Markdown/Block.hs
--- a/Text/Markdown/Block.hs
+++ b/Text/Markdown/Block.hs
@@ -229,6 +229,7 @@
                             Nothing -> False
                     isNonPara LineBlank = True
                     isNonPara LineFenced{} = True
+                    isNonPara LineBlockQuote{} = not $ msBlankBeforeBlockquote ms
                     isNonPara _ = False
                 (mfinal, ls) <- takeTillConsume (\x -> isNonPara (lineType ms x) || listStartIndent x)
                 maybe (return ()) leftover mfinal
diff --git a/Text/Markdown/Types.hs b/Text/Markdown/Types.hs
--- a/Text/Markdown/Types.hs
+++ b/Text/Markdown/Types.hs
@@ -72,6 +72,15 @@
       -- Default: @False@
       --
       -- Since 0.1.4
+
+    , msBlankBeforeBlockquote :: Bool
+      -- ^ If @True@, a blank line is required before the start of a blockquote.  Standard
+      -- markdown syntax does not require a blank line before a blockquote, but it is all
+      -- too easy for a > to end up at the beginning of a line by accident.
+      --
+      -- Default: @True@
+      --
+      -- Since 0.1.5
     }
 
 -- | See 'msFencedHandlers.
@@ -92,6 +101,7 @@
                                        Just l -> H.pre $ H.code H.! HA.class_ (H.toValue l) $ rendered
                                        Nothing -> H.pre $ H.code $ rendered
         , msLinkNewTab = False
+        , msBlankBeforeBlockquote = True
         }
 
 -- | Helper for creating a 'FHRaw'.
diff --git a/markdown.cabal b/markdown.cabal
--- a/markdown.cabal
+++ b/markdown.cabal
@@ -1,5 +1,5 @@
 Name:                markdown
-Version:             0.1.4
+Version:             0.1.5
 Synopsis:            Convert Markdown to HTML, with XSS protection
 Description:         This library leverages existing high-performance libraries (attoparsec, blaze-html, text, and conduit), and should integrate well with existing codebases.
 Homepage:            https://github.com/snoyberg/markdown
diff --git a/test/Block.hs b/test/Block.hs
--- a/test/Block.hs
+++ b/test/Block.hs
@@ -6,12 +6,15 @@
 import Data.Text (Text)
 import Data.Conduit
 import qualified Data.Conduit.List as CL
-import Text.Markdown (def)
+import Text.Markdown (def, MarkdownSettings(..))
 import Text.Markdown.Block
 import Data.Functor.Identity (runIdentity)
 
+checkWith :: MarkdownSettings -> Text -> [Block Text] -> Expectation
+checkWith ms md blocks = runIdentity (yield md $$ toBlocks ms =$ CL.consume) `shouldBe` blocks
+
 check :: Text -> [Block Text] -> Expectation
-check md blocks = runIdentity (yield md $$ toBlocks def =$ CL.consume) `shouldBe` blocks
+check = checkWith def
 
 blockSpecs :: Spec
 blockSpecs = do
@@ -62,6 +65,12 @@
             [ BlockQuote [BlockPara "foo"]
             , BlockQuote [BlockList Unordered $ Left "bar"]
             ]
+        it "require blank before blockquote" $ check
+            "foo\n> bar"
+            [ BlockPara "foo\n> bar" ]
+        it "no blank before blockquote" $ checkWith def { msBlankBeforeBlockquote = False }
+            "foo\n> bar"
+            [ BlockPara "foo", BlockQuote [BlockPara "bar"]]
     describe "indented code" $ do
         it "simple" $ check
             "    foo\n    bar\n"