diff --git a/doc/zmq_getsockopt.txt b/doc/zmq_getsockopt.txt
index 4dbce5bc..3feb762c 100644
--- a/doc/zmq_getsockopt.txt
+++ b/doc/zmq_getsockopt.txt
@@ -542,11 +542,13 @@ ZMQ_CURVE_PUBLICKEY: Retrieve current CURVE public key
 
 Retrieves the current long term public key for the socket. You can
 provide either a 32 byte buffer, to retrieve the binary key value, or
-a 40 byte buffer, to retrieve the key in a printable Z85 format.
+a 41 byte buffer, to retrieve the key in a printable Z85 format.
+NOTE: to fetch a printable key, the buffer must be 41 bytes large
+to hold the 40-char key value and one null byte.
 
 [horizontal]
 Option value type:: binary data or Z85 text string
-Option value size:: 32 or 40
+Option value size:: 32 or 41
 Default value:: null
 Applicable socket types:: all, when using TCP transport
 
@@ -556,11 +558,11 @@ ZMQ_CURVE_SECRETKEY: Retrieve current CURVE secret key
 
 Retrieves the current long term secret key for the socket. You can
 provide either a 32 byte buffer, to retrieve the binary key value, or
-a 40 byte buffer, to retrieve the key in a printable Z85 format.
+a 41 byte buffer, to retrieve the key in a printable Z85 format.
 
 [horizontal]
 Option value type:: binary data or Z85 text string
-Option value size:: 32 or 40
+Option value size:: 32 or 41
 Default value:: null
 Applicable socket types:: all, when using TCP transport
 
@@ -574,7 +576,7 @@ a 40 byte buffer, to retrieve the key in a printable Z85 format.
 
 [horizontal]
 Option value type:: binary data or Z85 text string
-Option value size:: 32 or 40
+Option value size:: 32 or 41
 Default value:: null
 Applicable socket types:: all, when using TCP transport
 
diff --git a/src/options.cpp b/src/options.cpp
index 50a0b8e8..9dd52511 100644
--- a/src/options.cpp
+++ b/src/options.cpp
@@ -590,7 +590,7 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
                 return 0;
             }
             else
-            if (*optvallen_ == CURVE_KEYSIZE_Z85) {
+            if (*optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                 Z85_encode ((char *) optval_, curve_public_key, CURVE_KEYSIZE);
                 return 0;
             }
@@ -602,7 +602,7 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
                 return 0;
             }
             else
-            if (*optvallen_ == CURVE_KEYSIZE_Z85) {
+            if (*optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                 Z85_encode ((char *) optval_, curve_secret_key, CURVE_KEYSIZE);
                 return 0;
             }
@@ -614,7 +614,7 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
                 return 0;
             }
             else
-            if (*optvallen_ == CURVE_KEYSIZE_Z85) {
+            if (*optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                 Z85_encode ((char *) optval_, curve_server_key, CURVE_KEYSIZE);
                 return 0;
             }
diff --git a/src/options.hpp b/src/options.hpp
index 208fe261..5154fab6 100644
--- a/src/options.hpp
+++ b/src/options.hpp
@@ -53,7 +53,7 @@ namespace zmq
         unsigned char identity_size;
         unsigned char identity [256];
 
-        //  Maximum tranfer rate [kb/s]. Default 100kb/s.
+        //  Maximum transfer rate [kb/s]. Default 100kb/s.
         int rate;
 
         //  Reliability time interval [ms]. Default 10 seconds.
diff --git a/src/z85_codec.hpp b/src/z85_codec.hpp
index dabdf652..e03a38b5 100644
--- a/src/z85_codec.hpp
+++ b/src/z85_codec.hpp
@@ -48,7 +48,8 @@ static uint8_t decoder [96] = {
 
 //  --------------------------------------------------------------------------
 //  Encode a binary frame as a string; destination string MUST be at least
-//  size * 5 / 4 bytes long. Returns dest. Size must be a multiple of 4.
+//  size * 5 / 4 bytes long plus 1 byte for the null terminator. Returns
+//  dest. Size must be a multiple of 4.
 
 char *
 Z85_encode (char *dest, uint8_t *data, size_t size)
diff --git a/tools/Makefile.am b/tools/Makefile.am
index d2bec2d7..ec565baa 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -1 +1,11 @@
 EXTRA_DIST = curve_keygen.c z85_codec.h
+
+INCLUDES = -I$(top_builddir)/include \
+           -I$(top_srcdir)/include
+# INCLUDES = -I$(top_srcdir)/include
+
+bin_PROGRAMS = curve_keygen
+
+curve_keygen_LDADD = $(top_builddir)/src/libzmq.la
+curve_keygen_SOURCES = curve_keygen.c
+
diff --git a/tools/z85_codec.h b/tools/z85_codec.h
index 523509d6..aa609f8b 100644
--- a/tools/z85_codec.h
+++ b/tools/z85_codec.h
@@ -50,7 +50,8 @@ static uint8_t decoder [96] = {
 
 //  --------------------------------------------------------------------------
 //  Encode a binary frame as a string; destination string MUST be at least
-//  size * 5 / 4 bytes long. Returns dest. Size must be a multiple of 4.
+//  size * 5 / 4 bytes long plus 1 byte for the null terminator. Returns
+//  dest. Size must be a multiple of 4.
 
 char *
 Z85_encode (char *dest, uint8_t *data, size_t size)