diff --git a/src/ext/ed25519/ref10/base.py b/src/ext/ed25519/ref10/base.py
index 84accc8580..8bfaab0568 100644
--- a/src/ext/ed25519/ref10/base.py
+++ b/src/ext/ed25519/ref10/base.py
@@ -1,3 +1,8 @@
+# Future imports for Python 2.7, mandatory in 3.0
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
 b = 256
 q = 2**255 - 19
 l = 2**252 + 27742317777372353535851937790883648493
diff --git a/src/ext/ed25519/ref10/base2.py b/src/ext/ed25519/ref10/base2.py
index 5e4e8739d0..5923e43a7b 100644
--- a/src/ext/ed25519/ref10/base2.py
+++ b/src/ext/ed25519/ref10/base2.py
@@ -1,3 +1,8 @@
+# Future imports for Python 2.7, mandatory in 3.0
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
 b = 256
 q = 2**255 - 19
 l = 2**252 + 27742317777372353535851937790883648493
diff --git a/src/ext/ed25519/ref10/d.py b/src/ext/ed25519/ref10/d.py
index 8995bb86a3..3fbb175077 100644
--- a/src/ext/ed25519/ref10/d.py
+++ b/src/ext/ed25519/ref10/d.py
@@ -1,3 +1,8 @@
+# Future imports for Python 2.7, mandatory in 3.0
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
 q = 2**255 - 19
 
 def expmod(b,e,m):
diff --git a/src/ext/ed25519/ref10/d2.py b/src/ext/ed25519/ref10/d2.py
index 79841758be..3e533730b7 100644
--- a/src/ext/ed25519/ref10/d2.py
+++ b/src/ext/ed25519/ref10/d2.py
@@ -1,3 +1,8 @@
+# Future imports for Python 2.7, mandatory in 3.0
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
 q = 2**255 - 19
 
 def expmod(b,e,m):
diff --git a/src/ext/ed25519/ref10/sqrtm1.py b/src/ext/ed25519/ref10/sqrtm1.py
index 9a47fbc12a..a276d4e673 100644
--- a/src/ext/ed25519/ref10/sqrtm1.py
+++ b/src/ext/ed25519/ref10/sqrtm1.py
@@ -1,3 +1,8 @@
+# Future imports for Python 2.7, mandatory in 3.0
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
 q = 2**255 - 19
 
 def expmod(b,e,m):