diff --git a/CHANGELOG.md b/CHANGELOG.md
index 53589708..eb37e020 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,9 @@ Modifications by (in alphabetical order):
 * P. Vitt, University of Siegen, Germany
 * A. Voysey, UK Met Office
 
+24/08/2026 PR #523 for #522. Adds an extension to support the (Intel-specific)
+           'directory=' and 'dirspec=' arguments to the INQUIRY function.
+
 16/07/2026 PR #520 for #519. Fix truncation of a character length expression that
            contains a comma (e.g. the arguments to an intrinsic such as
            MAX) when the kind appears before the length in a char-selector.
diff --git a/src/fparser/two/Fortran2003.py b/src/fparser/two/Fortran2003.py
index ecc89765..20acfe27 100644
--- a/src/fparser/two/Fortran2003.py
+++ b/src/fparser/two/Fortran2003.py
@@ -9758,6 +9758,10 @@ class Inquire_Spec(KeywordValueBase):  # R930
                          | STREAM = <scalar-default-char-variable>
                          | UNFORMATTED = <scalar-default-char-variable>
                          | WRITE = <scalar-default-char-variable>
+    If the extension `inquiry-directory` is enabled, it will also allow
+    the intel specific arguments:
+                         | DIRECTORY = <file-name-expr>
+                         | DIRSPEC = <scalar-default-char-variable>
 
     The `items` attribute for this class contains (str, instance).
 
@@ -9789,7 +9793,7 @@ def match(string):
             # The only argument which need not be named is the unit number
             return "UNIT", File_Unit_Number(string)
         # We have a keyword-value pair. Check whether it is valid...
-        for keyword, value in [
+        valid = [
             (
                 [
                     "ACCESS",
@@ -9825,13 +9829,21 @@ def match(string):
             ("IOMSG", Iomsg_Variable),
             ("FILE", File_Name_Expr),
             ("UNIT", File_Unit_Number),
-        ]:
+        ]
+
+        if "inquire-directory" in EXTENSIONS():
+            # Support the intel-specific extension:
+            valid.append(("DIRECTORY", File_Name_Expr))
+            valid.append(("DIRSPEC", Scalar_Default_Char_Variable))
+
+        for keyword, value in valid:
             try:
                 obj = KeywordValueBase.match(keyword, value, string, upper_lhs=True)
             except NoMatchError:
                 obj = None
             if obj is not None:
                 return obj
+
         return None
 
 
diff --git a/src/fparser/two/tests/test_fortran2003.py b/src/fparser/two/tests/test_fortran2003.py
index cfcefaa1..43f8f129 100644
--- a/src/fparser/two/tests/test_fortran2003.py
+++ b/src/fparser/two/tests/test_fortran2003.py
@@ -2346,9 +2346,16 @@ def test_inquire_stmt():
     assert str(obj) == "INQUIRE(UNIT = get_unit, OPENED = llopn)"
 
 
-def test_inquire_spec():
+@pytest.mark.parametrize("standard_only", [True, False])
+def test_inquire_spec(monkeypatch, standard_only):
     """Tests that we recognise the various possible forms of
     entries in an inquire list (R930)."""
+
+    if standard_only:
+        # Disable the inquire-directory extension for this test to verify
+        # that really only standard expressions are accepted
+        monkeypatch.setattr(utils, "_EXTENSIONS", [])
+
     tcls = Inquire_Spec
     obj = tcls("1")
     assert isinstance(obj, tcls), repr(obj)
@@ -2373,6 +2380,31 @@ def test_inquire_spec():
     assert isinstance(obj, tcls), repr(obj)
     assert str(obj) == "DIRECT = a"
 
+    if standard_only:
+        with pytest.raises(NoMatchError) as excinfo:
+            _ = tcls("directory = a")
+        assert "Inquire_Spec: 'directory = a" in str(excinfo.value)
+        with pytest.raises(NoMatchError) as excinfo:
+            _ = tcls("dirspec = a")
+        assert "Inquire_Spec: 'dirspec = a" in str(excinfo.value)
+    else:
+        obj = tcls("directory = a")
+        assert isinstance(obj, tcls), repr(obj)
+        assert str(obj) == "DIRECTORY = a"
+
+        obj = tcls("directory = 'some_dir'")
+        assert isinstance(obj, tcls), repr(obj)
+        assert str(obj) == "DIRECTORY = 'some_dir'"
+
+        obj = tcls("dirspec = some_var")
+        assert isinstance(obj, tcls), repr(obj)
+        assert str(obj) == "DIRSPEC = some_var"
+
+        # Make sure a character constant is not accepted:
+        with pytest.raises(NoMatchError) as excinfo:
+            _ = tcls("dirspec = 'a'")
+        assert "Inquire_Spec: 'dirspec = 'a'" in str(excinfo.value)
+
 
 def test_inquire_spec_list():
     """Tests that we recognise the various possible forms of
diff --git a/src/fparser/two/utils.py b/src/fparser/two/utils.py
index b7985a80..0fdefa2a 100644
--- a/src/fparser/two/utils.py
+++ b/src/fparser/two/utils.py
@@ -118,6 +118,10 @@
 # With this extension, these statements will be allowed.
 _EXTENSIONS += ["extended-stop-args"]
 
+# While non-standard, some compilers (Intel at least) support using inquire
+# with a directory, using e.g. INQUIRE (DIRECTORY=".", DIRSPEC=C_DIRSPEC, ...)
+_EXTENSIONS += ["inquire-directory"]
+
 
 def EXTENSIONS():
     """