diff --git a/tests/test_security_curve.cpp b/tests/test_security_curve.cpp
index 6f6f829b..ce9f1800 100644
--- a/tests/test_security_curve.cpp
+++ b/tests/test_security_curve.cpp
@@ -53,7 +53,7 @@ static void zap_handler (void *ctx)
         int size = zmq_recv (zap, client_key, 32, 0);
         assert (size == 32);
 
-        char client_key_text [40];
+        char client_key_text [41];
         Z85_encode (client_key_text, client_key, 32);
 
         assert (streq (version, "1.0"));
diff --git a/tools/curve_keygen.c b/tools/curve_keygen.c
index 157d6fb2..621d1d84 100644
--- a/tools/curve_keygen.c
+++ b/tools/curve_keygen.c
@@ -56,7 +56,7 @@ int main (void)
     int rc = crypto_box_keypair (public_key, secret_key);
     assert (rc == 0);
     
-    char encoded [40];
+    char encoded [41];
     Z85_encode (encoded, public_key, 32);
     puts ("\n== CURVE PUBLIC KEY ==");
     puts (encoded);