diff --git a/README.md b/README.md
index 45a82c8..a64d6f9 100644
--- a/README.md
+++ b/README.md
@@ -70,6 +70,20 @@ library API via command line.
 
 prints the usage.
 
+Convert PSL into DAFSA
+----------------------
+
+The [DAFSA](https://en.wikipedia.org/wiki/Deterministic_acyclic_finite_state_automaton) format is a compressed
+representation of strings. Here we use it to reduce the whole PSL to about 32k in size.
+
+Generate `psl.dafsa` from `list/public_suffix_list.dat`
+
+	$ src/make_dafsa.py --output-format=binary --input-format=psl list/public_suffix_list.dat psl.dafsa
+
+Test the result (example)
+
+	$ tools/psl --load-psl-file psl.dafsa aeroclub.aero
+
 License
 -------
 
diff --git a/src/make_dafsa.py b/src/make_dafsa.py
index 55dc181..e22aae6 100755
--- a/src/make_dafsa.py
+++ b/src/make_dafsa.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE.chromium file.
@@ -445,7 +445,7 @@ def words_to_cxx(words):
 
 def words_to_binary(words):
   """Generates C++ code from a word list"""
-  return words_to_whatever(words, bytearray)
+  return b'.DAFSA@PSL_0   \n' + words_to_whatever(words, bytearray)
 
 
 def parse_psl2c(infile):
diff --git a/src/psl.c b/src/psl.c
index d704fff..c3a4ffe 100644
--- a/src/psl.c
+++ b/src/psl.c
@@ -1110,8 +1110,7 @@ psl_ctx_t *psl_load_fp(FILE *fp)
 	psl_ctx_t *psl;
 	_psl_entry_t suffix, *suffixp;
 	char buf[256], *linep, *p;
-	size_t n;
-	int type = 0;
+	int type = 0, is_dafsa;
 	_psl_idna_t *idna;
 
 	if (!fp)
@@ -1121,14 +1120,18 @@ psl_ctx_t *psl_load_fp(FILE *fp)
 		return NULL;
 
 	/* read first line to allow ASCII / DAFSA detection */
-	if ((n = fread(buf, 1, sizeof(buf) - 1, fp)) < 1)
+	if (!(linep = fgets(buf, sizeof(buf) - 1, fp)))
 		goto fail;
 
-	buf[n] = 0;
+	is_dafsa = strlen(buf) == 16 && !strncmp(buf, ".DAFSA@PSL_", 11);
 
-	if (!strstr(buf, "This Source Code Form is subject to")) {
+	if (is_dafsa) {
 		void *m;
-		size_t size = 65536, len = n;
+		size_t size = 65536, n, len = 0;
+		int version = atoi(buf + 11);
+
+		if (version != 0)
+			goto fail;
 
 		if (!(psl->dafsa = malloc(size)))
 			goto fail;
@@ -1148,11 +1151,11 @@ psl_ctx_t *psl_load_fp(FILE *fp)
 		if ((m = realloc(psl->dafsa, len)))
 			psl->dafsa = m;
 
+		psl->dafsa_size = len;
+
 		return psl;
 	}
 
-	rewind(fp);
-
 	idna = _psl_idna_open();
 
 	/*
@@ -1161,7 +1164,7 @@ psl_ctx_t *psl_load_fp(FILE *fp)
 	 */
 	psl->suffixes = _vector_alloc(8*1024, _suffix_compare_array);
 
-	while ((linep = fgets(buf, sizeof(buf), fp))) {
+	do {
 		while (_isspace_ascii(*linep)) linep++; /* ignore leading whitespace */
 		if (!*linep) continue; /* skip empty lines */
 
@@ -1232,7 +1235,7 @@ psl_ctx_t *psl_load_fp(FILE *fp)
 
 			_add_punycode_if_needed(idna, psl->suffixes, suffixp);
 		}
-	}
+	} while ((linep = fgets(buf, sizeof(buf), fp)));
 
 	_vector_sort(psl->suffixes);