diff --git a/src/calibre/utils/formatter.py b/src/calibre/utils/formatter.py
index eff38203a0..2fa5901dde 100644
--- a/src/calibre/utils/formatter.py
+++ b/src/calibre/utils/formatter.py
@@ -137,6 +137,7 @@ class _Parser(object):
             # We have a function.
             # Check if it is a known one. We do this here so error reporting is
             # better, as it can identify the tokens near the problem.
+            id = id.strip()
             if id not in funcs:
                 self.error(_('unknown function {0}').format(id))
 
@@ -246,6 +247,7 @@ class _CompileParser(_Parser):
             # We have a function.
             # Check if it is a known one. We do this here so error reporting is
             # better, as it can identify the tokens near the problem.
+            id = id.strip()
             if id not in funcs:
                 self.error(_('unknown function {0}').format(id))
 
@@ -457,7 +459,7 @@ class TemplateFormatter(string.Formatter):
                     colon += 1
 
                 funcs = formatter_functions().get_functions()
-                fname = fmt[colon:p]
+                fname = fmt[colon:p].strip()
                 if fname in funcs:
                     func = funcs[fname]
                     if func.arg_count == 2: