diff --git a/lib/mdless/converter.rb b/lib/mdless/converter.rb
index d1e91d3..e54e454 100644
--- a/lib/mdless/converter.rb
+++ b/lib/mdless/converter.rb
@@ -634,7 +634,7 @@ def convert_markdown(input)
         else
           first_line = m[3].to_s.split(/\n/)[0]
 
-          if first_line =~ /^\s*#!/
+          if first_line =~ /^\s*#!.*\/.+/
             shebang = first_line.match(/^\s*#!.*\/(?:env )?([^\/]+)$/)
             language = shebang[1]
             code_block = m[3]
diff --git a/test/codeblocks.md b/test/codeblocks.md
index aa65bea..b466a24 100644
--- a/test/codeblocks.md
+++ b/test/codeblocks.md
@@ -4,6 +4,10 @@ date: yesterday
 Code block tests
 ================
 
+```
+#!
+```
+
 Just some text before we get started.
 
 ![Image test](https://raw.githubusercontent.com/eddieantonio/i/master/imgcat.png)<br/>after a break