diff --git a/CHANGES b/CHANGES
index 077ea77..b6c56fb 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,5 @@
 0.28:
+  add uint64 pack and unpack routines
 
 0.27:
   add fmt_strm
diff --git a/test/uint.c b/test/uint.c
new file mode 100644
index 0000000..b8e87f3
--- /dev/null
+++ b/test/uint.c
@@ -0,0 +1,66 @@
+#include <assert.h>
+#include <uint16.h>
+#include <uint32.h>
+#include <uint64.h>
+#include <byte.h>
+
+int main() {
+  char buf[8];
+
+  {
+    uint16 a;
+
+    buf[0]=buf[1]=0;
+    uint16_pack_big(buf,0x1234);
+    assert(buf[0]==0x12 && buf[1]==0x34);
+    uint16_unpack_big(buf,&a);
+    assert(a==0x1234);
+    assert(uint16_read_big(buf)==0x1234);
+
+    buf[0]=buf[1]=0;
+    uint16_pack(buf,0x1234);
+    assert(buf[0]==0x34 && buf[1]==0x12);
+    uint16_unpack(buf,&a);
+    assert(a==0x1234);
+    assert(uint16_read(buf)==0x1234);
+  }
+
+  {
+    uint32 a;
+
+    buf[0]=buf[1]=buf[2]=buf[3]=0;
+    uint32_pack_big(buf,0x12345678);
+    assert(buf[0]==0x12 && buf[1]==0x34 && buf[2]==0x56 && buf[3]==0x78);
+    uint32_unpack_big(buf,&a);
+    assert(a==0x12345678);
+    assert(uint32_read_big(buf)==0x12345678);
+
+    buf[0]=buf[1]=buf[2]=buf[3]=0;
+    uint32_pack(buf,0x12345678);
+    assert(buf[0]==0x78 && buf[1]==0x56 && buf[2]==0x34 && buf[3]==0x12);
+    uint32_unpack(buf,&a);
+    assert(a==0x12345678);
+    assert(uint32_read(buf)==0x12345678);
+  }
+
+  {
+    uint64 a;
+    unsigned int i;
+
+    byte_zero(buf,sizeof(buf));
+    uint64_pack_big(buf,0x0102030405060708ull);
+    for (i=0; i<8; ++i) assert(buf[i]==i+1);
+    uint64_unpack_big(buf,&a);
+    assert(a==0x0102030405060708ull);
+    assert(uint64_read_big(buf)==0x0102030405060708ull);
+
+    byte_zero(buf,sizeof(buf));
+    uint64_pack(buf,0x0102030405060708ull);
+    for (i=0; i<8; ++i) assert(buf[7-i]==i+1);
+    uint64_unpack(buf,&a);
+    assert(a==0x0102030405060708ull);
+    assert(uint64_read(buf)==0x0102030405060708ull);
+  }
+
+
+}
diff --git a/uint/uint32_pack_big.3 b/uint/uint32_pack_big.3
index 3ab8311..84c15c5 100644
--- a/uint/uint32_pack_big.3
+++ b/uint/uint32_pack_big.3
@@ -11,7 +11,7 @@ void \fBuint32_pack_big\fP(char \fIs\fR[4],uint32 \fIu\fR);
 uint32 is a 32-bit unsigned integer type, normally either unsigned int
 or unsigned long.
 
-uint32_pack_big portably writes a uint16 \fIu\fR to \fIs\fR in
+uint32_pack_big portably writes a uint32 \fIu\fR to \fIs\fR in
 big-endian (i.e. network) byte order.
 
 .SH "SEE ALSO"
diff --git a/uint/uint64_pack.3 b/uint/uint64_pack.3
new file mode 100644
index 0000000..b901d6b
--- /dev/null
+++ b/uint/uint64_pack.3
@@ -0,0 +1,17 @@
+.TH uint64_pack 3
+.SH NAME
+uint64_pack \- write an unsigned little-endian 64-bit integer
+.SH SYNTAX
+.B #include <uint64.h>
+
+uint64 \fIu\fR;
+
+void \fBuint64_pack\fP(char \fIs\fR[4],uint64 \fIu\fR);
+.SH DESCRIPTION
+uint64 is a 64-bit unsigned integer type.
+
+uint64_pack portably writes a uint64 \fIu\fR to \fIs\fR in
+little-endian byte order.
+
+.SH "SEE ALSO"
+uint64_unpack(3), uint64_pack_big(3)
diff --git a/uint/uint64_pack.c b/uint/uint64_pack.c
new file mode 100644
index 0000000..bb9a8ba
--- /dev/null
+++ b/uint/uint64_pack.c
@@ -0,0 +1,8 @@
+#define NO_UINT64_MACROS
+#include "uint64.h"
+#include "uint32.h"
+
+void uint64_pack(char *out,uint64 in) {
+  uint32_pack(out,in&0xffffffff);
+  uint32_pack(out+4,in>>32);
+}
diff --git a/uint/uint64_pack_big.3 b/uint/uint64_pack_big.3
new file mode 100644
index 0000000..3c683eb
--- /dev/null
+++ b/uint/uint64_pack_big.3
@@ -0,0 +1,17 @@
+.TH uint64_pack_big 3
+.SH NAME
+uint64_pack_big \- write an unsigned big-endian 64-bit integer
+.SH SYNTAX
+.B #include <uint64.h>
+
+uint64 \fIu\fR;
+
+void \fBuint64_pack_big\fP(char \fIs\fR[4],uint64 \fIu\fR);
+.SH DESCRIPTION
+uint64 is a 64-bit unsigned integer type.
+
+uint64_pack_big portably writes a uint64 \fIu\fR to \fIs\fR in
+big-endian (i.e. network) byte order.
+
+.SH "SEE ALSO"
+uint64_unpack_big(3), uint64_pack(3)
diff --git a/uint/uint64_pack_big.c b/uint/uint64_pack_big.c
new file mode 100644
index 0000000..7948bc6
--- /dev/null
+++ b/uint/uint64_pack_big.c
@@ -0,0 +1,8 @@
+#define NO_UINT64_MACROS
+#include "uint64.h"
+#include "uint32.h"
+
+void uint64_pack_big(char *out,uint64 in) {
+  uint32_pack_big(out,in>>32);
+  uint32_pack_big(out+4,in&0xffffffff);
+}
diff --git a/uint/uint64_read.3 b/uint/uint64_read.3
new file mode 100644
index 0000000..78b04aa
--- /dev/null
+++ b/uint/uint64_read.3
@@ -0,0 +1,15 @@
+.TH uint64_read 3
+.SH NAME
+uint64_read \- read an unsigned little-endian 64-bit integer
+.SH SYNTAX
+.B #include <uint64.h>
+
+uint64 \fBuint64_read\fP(const char \fIs\fR[4]);
+.SH DESCRIPTION
+uint64 is a 64-bit unsigned integer type.
+
+uint64_read portably reads a uint64 as stored on a little-endian
+architecture from \fIs\fR and returns it.
+
+.SH "SEE ALSO"
+uint64_unpack(3), uint64_unpack_big(3)
diff --git a/uint/uint64_read.c b/uint/uint64_read.c
new file mode 100644
index 0000000..b9051b6
--- /dev/null
+++ b/uint/uint64_read.c
@@ -0,0 +1,7 @@
+#define NO_UINT64_MACROS
+#include "uint64.h"
+#include "uint32.h"
+
+uint64 uint64_read(const char *in) {
+  return uint32_read(in) | ((uint64)uint32_read(in+4)<<32);
+}
diff --git a/uint/uint64_read_big.3 b/uint/uint64_read_big.3
new file mode 100644
index 0000000..7d5e08f
--- /dev/null
+++ b/uint/uint64_read_big.3
@@ -0,0 +1,15 @@
+.TH uint64_read_big 3
+.SH NAME
+uint64_read_big \- read an unsigned big-endian 64-bit integer
+.SH SYNTAX
+.B #include <uint64.h>
+
+uint64 \fBuint64_read_big\fP(const char \fIs\fR[4]);
+.SH DESCRIPTION
+uint64 is a 64-bit unsigned integer type.
+
+uint64_read_big portably reads a uint64 as stored on a big-endian
+architecture from \fIs\fR and returns it.
+
+.SH "SEE ALSO"
+uint64_unpack(3), uint64_unpack_big(3)
diff --git a/uint/uint64_read_big.c b/uint/uint64_read_big.c
new file mode 100644
index 0000000..02261a5
--- /dev/null
+++ b/uint/uint64_read_big.c
@@ -0,0 +1,7 @@
+#define NO_UINT64_MACROS
+#include "uint64.h"
+#include "uint32.h"
+
+uint64 uint64_read_big(const char *in) {
+  return ((uint64)uint32_read_big(in)<<32) | uint32_read_big(in+4);
+}
diff --git a/uint/uint64_unpack.3 b/uint/uint64_unpack.3
new file mode 100644
index 0000000..c1bc00d
--- /dev/null
+++ b/uint/uint64_unpack.3
@@ -0,0 +1,17 @@
+.TH uint64_unpack 3
+.SH NAME
+uint64_unpack \- read an unsigned little-endian 64-bit integer
+.SH SYNTAX
+.B #include <uint64.h>
+
+uint64 \fIu\fR;
+
+void \fBuint64_unpack\fP(const char \fIs\fR[4],uint64 *\fIu\fR);
+.SH DESCRIPTION
+uint64 is a 64-bit unsigned integer type.
+
+uint64_unpack portably reads a uint64 as stored on a little-endian
+architecture from \fIs\fR and writes it into \fIu\fR in the native byte order.
+
+.SH "SEE ALSO"
+uint64_pack(3), uint64_unpack_big(3)
diff --git a/uint/uint64_unpack.c b/uint/uint64_unpack.c
new file mode 100644
index 0000000..c602c94
--- /dev/null
+++ b/uint/uint64_unpack.c
@@ -0,0 +1,7 @@
+#define NO_UINT64_MACROS
+#include "uint64.h"
+#include "uint32.h"
+
+void uint64_unpack(const char *in,uint64 *out) {
+  *out = uint64_read(in);
+}
diff --git a/uint/uint64_unpack_big.3 b/uint/uint64_unpack_big.3
new file mode 100644
index 0000000..473ca58
--- /dev/null
+++ b/uint/uint64_unpack_big.3
@@ -0,0 +1,18 @@
+.TH uint64_unpack_big 3
+.SH NAME
+uint64_unpack_big \- read an unsigned big-endian 64-bit integer
+.SH SYNTAX
+.B #include <uint64.h>
+
+uint64 \fIu\fR;
+
+void \fBuint64_unpack_big\fP(const char \fIs\fR[4],uint64 *\fIu\fR);
+.SH DESCRIPTION
+uint64 is a 64-bit unsigned integer type.
+
+uint64_unpack_big portably reads a uint64 as stored on a big-endian
+architecture (i.e. in network byte order) from \fIs\fR and writes it
+into \fIu\fR in the native byte order.
+
+.SH "SEE ALSO"
+uint64_pack_big(3), uint64_unpack(3)
diff --git a/uint/uint64_unpack_big.c b/uint/uint64_unpack_big.c
new file mode 100644
index 0000000..7b2af4e
--- /dev/null
+++ b/uint/uint64_unpack_big.c
@@ -0,0 +1,7 @@
+#define NO_UINT64_MACROS
+#include "uint64.h"
+#include "uint32.h"
+
+void uint64_unpack_big(const char *in,uint64 *out) {
+  *out = uint64_read_big(in);
+}
diff --git a/uint16.h b/uint16.h
index b7726f3..f1e7324 100644
--- a/uint16.h
+++ b/uint16.h
@@ -6,7 +6,7 @@
 typedef uint16_t uint16;
 typedef int16_t int16;
 
-#if defined(__i386__) && !defined(NO_UINT16_MACROS)
+#if (defined(__i386__) || defined(__x86_64__)) && !defined(NO_UINT16_MACROS)
 #define uint16_pack(out,in) (*(uint16*)(out)=(in))
 #define uint16_unpack(in,out) (*(out)=*(uint16*)(in))
 #define uint16_read(in) (*(uint16*)(in))
diff --git a/uint32.h b/uint32.h
index 8748f5c..fbfe039 100644
--- a/uint32.h
+++ b/uint32.h
@@ -6,7 +6,7 @@
 typedef uint32_t uint32;
 typedef int32_t int32;
 
-#if defined(__i386__) && !defined(NO_UINT32_MACROS)
+#if (defined(__i386__) || defined(__x86_64__)) && !defined(NO_UINT32_MACROS)
 #define uint32_pack(out,in) (*(uint32*)(out)=(in))
 #define uint32_unpack(in,out) (*(out)=*(uint32*)(in))
 #define uint32_read(in) (*(uint32*)(in))
diff --git a/uint64.h b/uint64.h
index 5209109..8188fe8 100644
--- a/uint64.h
+++ b/uint64.h
@@ -6,4 +6,22 @@
 typedef uint64_t uint64;
 typedef int64_t int64;
 
+#if (defined(__i386__) || defined(__x86_64__)) && !defined(NO_UINT64_MACROS)
+#define uint64_pack(out,in) (*(uint64*)(out)=(in))
+#define uint64_unpack(in,out) (*(out)=*(uint64*)(in))
+#define uint64_read(in) (*(uint64*)(in))
+void uint64_pack_big(char *out,uint64 in);
+void uint64_unpack_big(const char *in,uint64* out);
+uint64 uint64_read_big(const char *in);
+#else
+
+void uint64_pack(char *out,uint64 in);
+void uint64_pack_big(char *out,uint64 in);
+void uint64_unpack(const char *in,uint64* out);
+void uint64_unpack_big(const char *in,uint64* out);
+uint64 uint64_read(const char *in);
+uint64 uint64_read_big(const char *in);
+
+#endif
+
 #endif