diff --git a/nix/fasm/default.nix b/nix/fasm/default.nix
index 4d27b1c..a3b7e03 100644
--- a/nix/fasm/default.nix
+++ b/nix/fasm/default.nix
@@ -33,7 +33,9 @@ buildPythonPackage rec {
     hash = "sha256-oC6vSpI9u8gEA2C85k00WdXzpH5GxeqtfNqqMduW5Jg=";
   };
 
-  patches = map fetchPatchFromAur [
+  patches = [
+    ./textx-default.patch
+  ] ++ (map fetchPatchFromAur [
     {
       name = "0001-cmake-install-parse_fasm.so.patch";
       sha256 = "sha256-ZEq/hTXjCIkVkWhgCYWtRe3wftdYMNwhNC4KNnBI2Dc=";
@@ -70,7 +72,7 @@ buildPythonPackage rec {
       name = "0009-Use-cmake-directly-instead-of-letting-setup.py-try-t.patch";
       sha256 = "sha256-/Ay+XjTE7MPcQg5yeo7zuKE2T/tE/P1sIMxgRYeSWNI=";
     }
-  ];
+  ]);
 
 
   nativeBuildInputs = [
diff --git a/nix/fasm/textx-default.patch b/nix/fasm/textx-default.patch
new file mode 100644
index 0000000..f1e907c
--- /dev/null
+++ b/nix/fasm/textx-default.patch
@@ -0,0 +1,32 @@
+diff --git a/fasm/parser/__init__.py b/fasm/parser/__init__.py
+index edd02e4..9d188e0 100644
+--- a/fasm/parser/__init__.py
++++ b/fasm/parser/__init__.py
+@@ -22,25 +22,8 @@ from warnings import warn
+ available = []
+ """ List of parser submodules available. Strings should match module names. """
+ 
+-try:
+-    from fasm.parser.antlr import \
+-        parse_fasm_filename, parse_fasm_string, implementation
+-    available.append('antlr')
+-except ImportError as e:
+-    warn(
+-        """Unable to import fast Antlr4 parser implementation.
+-  ImportError: {}
+-
+-  Falling back to the much slower pure Python textX based parser
+-  implementation.
+-
+-  Getting the faster antlr parser can normally be done by installing the
+-  required dependencies and then reinstalling the fasm package with:
+-    pip uninstall
+-    pip install -v fasm
+-""".format(e), RuntimeWarning)
+-    from fasm.parser.textx import \
+-        parse_fasm_filename, parse_fasm_string, implementation
++from fasm.parser.textx import \
++    parse_fasm_filename, parse_fasm_string, implementation
+ 
+ # The textx parser is available as a fallback.
+ available.append('textx')