diff --git a/extra/math/primes/erato/authors.txt b/extra/math/primes/erato/authors.txt
new file mode 100644
index 0000000000..f3b0233f74
--- /dev/null
+++ b/extra/math/primes/erato/authors.txt
@@ -0,0 +1 @@
+Samuel Tardieu
diff --git a/extra/math/primes/erato/erato.factor b/extra/math/primes/erato/erato.factor
index effcd7b135..70a9c10ff5 100644
--- a/extra/math/primes/erato/erato.factor
+++ b/extra/math/primes/erato/erato.factor
@@ -1,3 +1,5 @@
+! Copyright (C) 2009 Samuel Tardieu.
+! See http://factorcode.org/license.txt for BSD license.
 USING: bit-arrays kernel math math.functions math.ranges sequences ;
 IN: math.primes.erato
 
diff --git a/extra/math/primes/erato/summary.txt b/extra/math/primes/erato/summary.txt
new file mode 100644
index 0000000000..6ecb893cd5
--- /dev/null
+++ b/extra/math/primes/erato/summary.txt
@@ -0,0 +1 @@
+Eratosthene sieve