diff --git a/doc/en/usage.txt b/doc/en/usage.txt
index d82061d6a..e43f4ff8c 100644
--- a/doc/en/usage.txt
+++ b/doc/en/usage.txt
@@ -67,13 +67,13 @@ Examples for modifying traceback printing::
     py.test --tb=short   # a shorter traceback format
     py.test --tb=line    # only one line per failure
 
-Dropping to PDB (Python Debugger) on failures
-----------------------------------------------
+Dropping to PDB_ (Python Debugger) on failures
+-----------------------------------------------
 
 .. _PDB: http://docs.python.org/library/pdb.html
 
 Python comes with a builtin Python debugger called PDB_.  ``pytest``
-allows one to drop into the PDB prompt via a command line option::
+allows one to drop into the PDB_ prompt via a command line option::
 
     py.test --pdb
 
@@ -98,7 +98,7 @@ can use a helper::
 
 .. versionadded: 2.0.0
 
-In previous versions you could only enter PDB tracing if
+In previous versions you could only enter PDB_ tracing if
 you disabled capturing on the command line via ``py.test -s``.
 
 .. _durations: