diff --git a/proton-c/bindings/php/proton.php b/proton-c/bindings/php/proton.php
index 16025e1..3dc398c 100644
--- a/proton-c/bindings/php/proton.php
+++ b/proton-c/bindings/php/proton.php
@@ -492,7 +492,11 @@
   }
 
   public function __tostring() {
-    return "UUID($this->bytes)";
+    $b = $this->bytes;
+    return sprintf("UUID(%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x)",
+                   ord($b[0]), ord($b[1]), ord($b[2]), ord($b[3]),
+                   ord($b[4]), ord($b[5]), ord($b[6]), ord($b[7]), ord($b[8]), ord($b[9]),
+                   ord($b[10]), ord($b[11]), ord($b[12]), ord($b[13]), ord($b[14]), ord($b[15]));
   }
 
 }
diff --git a/proton-c/include/proton/cproton.i b/proton-c/include/proton/cproton.i
index 669ec04..d04fab7 100644
--- a/proton-c/include/proton/cproton.i
+++ b/proton-c/include/proton/cproton.i
@@ -19,9 +19,12 @@
 typedef unsigned int size_t;
 typedef signed int ssize_t;
 typedef unsigned char uint8_t;
+typedef signed char int8_t;
+typedef unsigned short uint16_t;
+typedef signed short int16_t;
 typedef unsigned long int uint32_t;
-typedef unsigned long long int uint64_t;
 typedef long int int32_t;
+typedef unsigned long long int uint64_t;
 typedef long long int int64_t;
 
 /* Parse these interface header files to generate APIs for script languages */