diff --git a/bash_kernel.py b/bash_kernel.py
index c8b63e0..2318e08 100644
--- a/bash_kernel.py
+++ b/bash_kernel.py
@@ -77,19 +77,23 @@ class BashKernel(Kernel):
 
     def do_complete(self, code, cursor_pos):
         code = code[:cursor_pos]
+        default = {'matches': [], 'cursor_start': 0,
+                   'cursor_end': cursor_pos, 'metadata': dict(),
+                   'status': 'ok'}
         if code[-1] == ' ':
-            return
+            return default
         tokens = code.replace(';', ' ').split()
         if not tokens:
-            return
+            return default
         token = tokens[-1]
-        # check for valid function name
-        if not re.match('\A[a-zA-Z_]', token):
-            return
         start = cursor_pos - len(token)
-        cmd = 'compgen -c %s' % token
+        cmd = 'compgen -cdfa %s' % token
         output = self.bashwrapper.run_command(cmd).rstrip()
-        return {'matches': output.split(), 'cursor_start': start,
+        matches = output.split()
+        if not matches:
+            return default
+        matches = [m for m in matches if m.startswith(token)]
+        return {'matches': matches, 'cursor_start': start,
                 'cursor_end': cursor_pos, 'metadata': dict(),
                 'status': 'ok'}