diff --git a/loopy/frontend/fortran/__init__.py b/loopy/frontend/fortran/__init__.py
index c5c1943ca6a8e43be1f218920f21b4dc1f16c4e1..fa5c5050f47f220d895fc7c0229558a4f67f6f25 100644
--- a/loopy/frontend/fortran/__init__.py
+++ b/loopy/frontend/fortran/__init__.py
@@ -294,13 +294,8 @@ def _add_assignees_to_calls(knl, all_kernels):
 
 
 def parse_fortran(source, filename="<floopy code>", free_form=None, strict=None,
-        seq_dependencies=None, auto_dependencies=None, target=None,
-        all_names_known=True):
+        seq_dependencies=None, auto_dependencies=None, target=None):
     """
-    :arg all_names_known: if set to *False*, enter an undocumented mode
-        in which Fortran parsing will try to tolerate unknown names.
-        If used, ``loopy.frontend.fortran.translator.specialize_fortran_division``
-        must be called as soon as all names are known.
     :returns: a :class:`loopy.TranslationUnit`
     """
 
@@ -338,8 +333,7 @@ def parse_fortran(source, filename="<floopy code>", free_form=None, strict=None,
                 "and returned invalid data (Sorry!)")
 
     from loopy.frontend.fortran.translator import F2LoopyTranslator
-    f2loopy = F2LoopyTranslator(
-            filename, target=target, all_names_known=all_names_known)
+    f2loopy = F2LoopyTranslator(filename, target=target)
     f2loopy(tree)
 
     kernels = f2loopy.make_kernels(seq_dependencies=seq_dependencies)
diff --git a/loopy/frontend/fortran/translator.py b/loopy/frontend/fortran/translator.py
index e04e2cb78b96f8f6f000843b76a2291bf18b44a0..6b6c75622c67e7cb8656359f3ea17ca6fdc9d7e4 100644
--- a/loopy/frontend/fortran/translator.py
+++ b/loopy/frontend/fortran/translator.py
@@ -329,11 +329,10 @@ def specialize_fortran_division(t_unit):
 # {{{ translator
 
 class F2LoopyTranslator(FTreeWalkerBase):
-    def __init__(self, filename, target=None, all_names_known=True):
+    def __init__(self, filename, target=None):
         FTreeWalkerBase.__init__(self, filename)
 
         self.target = target
-        self.all_names_known = all_names_known
 
         self.scope_stack = []
 
diff --git a/test/test_numa_diff.py b/test/test_numa_diff.py
index bfe7c8756a3dc3b12e1dcdce635c5287665018ee..8ba55629877e77b184f9d075e89e3aa5ab758d1f 100644
--- a/test/test_numa_diff.py
+++ b/test/test_numa_diff.py
@@ -57,8 +57,7 @@ def test_gnuma_horiz_kernel(ctx_factory, ilp_multiple, Nq, opt_level):  # noqa
 
     source = source.replace("datafloat", "real*4")
 
-    program = lp.parse_fortran(source, filename, seq_dependencies=False,
-               all_names_known=False)
+    program = lp.parse_fortran(source, filename, seq_dependencies=False)
 
     hsv_r, hsv_s = program["strongVolumeKernelR"], program["strongVolumeKernelS"]