diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index e1ed0519bf..9638c1676d 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -90,7 +90,7 @@ int libxl_domain_make(libxl_ctx *ctx, libxl_domain_create_info *info,
     xs_transaction_t t;
     xen_domain_handle_t handle;
 
-    uuid_string = libxl_uuid2string(ctx, info->uuid);
+    uuid_string = libxl_uuid2string(&gc, info->uuid);
     if (!uuid_string) {
         libxl_free_all(&gc);
         return ERROR_NOMEM;
@@ -453,7 +453,7 @@ int libxl_domain_preserve(libxl_ctx *ctx, uint32_t domid,
         return ERROR_NOMEM;
     }
 
-    uuid_string = libxl_uuid2string(ctx, new_uuid);
+    uuid_string = libxl_uuid2string(&gc, new_uuid);
     if (!uuid_string) {
         libxl_free_all(&gc);
         return ERROR_NOMEM;
@@ -2764,7 +2764,7 @@ int libxl_set_memory_target(libxl_ctx *ctx, uint32_t domid, uint32_t target_memk
     if (rc != 1 || info.domain != domid)
         goto out;
     xcinfo2xlinfo(&info, &ptr);
-    uuid = libxl_uuid2string(ctx, ptr.uuid);
+    uuid = libxl_uuid2string(&gc, ptr.uuid);
     libxl_xs_write(&gc, XBT_NULL, libxl_sprintf(&gc, "/vm/%s/memory", uuid), "%"PRIu32, target_memkb / 1024);
 
     if (enforce || !domid)
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index fe117377c5..b6e70b690d 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -132,6 +132,12 @@
 #include <sys/wait.h> /* for pid_t */
 
 typedef uint8_t libxl_uuid[16];
+#define LIBXL_UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
+#define LIBXL_UUID_BYTES(uuid) uuid[0], uuid[1], uuid[2], uuid[3], \
+            uuid[4], uuid[5], uuid[6], uuid[7], \
+            uuid[8], uuid[9], uuid[10], uuid[11], \
+            uuid[12], uuid[13], uuid[14], uuid[15] \
+
 
 typedef uint8_t libxl_mac[6];
 
@@ -477,7 +483,6 @@ int libxl_run_bootloader(libxl_ctx *ctx,
                          libxl_device_disk *disk,
                          uint32_t domid);
 
-char *libxl_uuid2string(libxl_ctx *ctx, const libxl_uuid uuid);
   /* 0 means ERROR_ENOMEM, which we have logged */
 
 /* events handling */
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 4fe018d7ef..16918580d0 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -442,19 +442,12 @@ int save_device_model(libxl_ctx *ctx, uint32_t domid, int fd)
     return 0;
 }
 
-char *libxl_uuid2string(libxl_ctx *ctx, const libxl_uuid uuid)
+char *libxl_uuid2string(libxl_gc *gc, const libxl_uuid uuid)
 {
-    libxl_gc gc = LIBXL_INIT_GC(ctx);
-    char *s = string_of_uuid(&gc, uuid);
-    char *ret;
-    if (!s) {
-        XL_LOG(ctx, XL_LOG_ERROR, "cannot allocate for uuid");
-        ret = NULL;
-    }else{
-        ret = strdup(s);
-    }
-    libxl_free_all(&gc);
-    return ret;
+    char *s = libxl_sprintf(gc, LIBXL_UUID_FMT, LIBXL_UUID_BYTES(uuid));
+    if (!s)
+        XL_LOG(libxl_gc_owner(gc), XL_LOG_ERROR, "cannot allocate for uuid");
+    return s;
 }
 
 static const char *userdata_path(libxl_gc *gc, uint32_t domid,
@@ -472,7 +465,7 @@ static const char *userdata_path(libxl_gc *gc, uint32_t domid,
                      " for domain %"PRIu32, domid);
         return NULL;
     }
-    uuid_string = string_of_uuid(gc, info.uuid);
+    uuid_string = libxl_sprintf(gc, LIBXL_UUID_FMT, LIBXL_UUID_BYTES(info.uuid));
 
     path = libxl_sprintf(gc, "/var/lib/xen/"
                          "userdata-%s.%s.%s",
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index ec75dbbdb0..ffc213c82f 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -106,12 +106,6 @@ typedef struct {
 
 #define PRINTF_ATTRIBUTE(x, y) __attribute__((format(printf, x, y)))
 
-#define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
-#define string_of_uuid(ctx, u) \
-    libxl_sprintf(ctx, UUID_FMT, \
-                (u)[0], (u)[1], (u)[2], (u)[3], (u)[4], (u)[5], (u)[6], (u)[7], \
-                (u)[8], (u)[9], (u)[10], (u)[11], (u)[12], (u)[13], (u)[14], (u)[15])
-
 _hidden int xs_writev(struct xs_handle *xsh, xs_transaction_t t, char *dir, char *kvs[]);
 
 typedef struct {
@@ -267,4 +261,6 @@ const char *libxl_blktap_devpath(libxl_gc *gc,
                                  const char *disk,
                                  libxl_disk_phystype phystype);
 
+_hidden char *libxl_uuid2string(libxl_gc *gc, const libxl_uuid uuid);
+
 #endif
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 94a625a39f..44f1a135b4 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -41,8 +41,6 @@
 #include "libxlutil.h"
 #include "xl.h"
 
-#define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
-
 #define CHK_ERRNO( call ) ({                                            \
         int chk_errno = (call);                                         \
         if (chk_errno < 0) {                                                \
@@ -393,11 +391,7 @@ static void printf_info(int domid,
     printf("\t(oos %d)\n", c_info->oos);
     printf("\t(ssidref %d)\n", c_info->ssidref);
     printf("\t(name %s)\n", c_info->name);
-    printf("\t(uuid " UUID_FMT ")\n",
-           (c_info->uuid)[0], (c_info->uuid)[1], (c_info->uuid)[2], (c_info->uuid)[3],
-           (c_info->uuid)[4], (c_info->uuid)[5], (c_info->uuid)[6], (c_info->uuid)[7],
-           (c_info->uuid)[8], (c_info->uuid)[9], (c_info->uuid)[10], (c_info->uuid)[11],
-           (c_info->uuid)[12], (c_info->uuid)[13], (c_info->uuid)[14], (c_info->uuid)[15]);
+    printf("\t(uuid " LIBXL_UUID_FMT ")\n", LIBXL_UUID_BYTES(c_info->uuid));
     printf("\t(cpupool %s (%d))\n", c_info->poolname, c_info->poolid);
     if (c_info->xsdata)
         printf("\t(xsdata contains data)\n");
@@ -2188,10 +2182,8 @@ void list_domains(int verbose, const libxl_dominfo *info, int nb_domain)
                 info[i].dying ? 'd' : '-',
                 ((float)info[i].cpu_time / 1e9));
         free(domname);
-        if (verbose) {
-            char *uuid = libxl_uuid2string(&ctx, info[i].uuid);
-            printf(" %s", uuid);
-        }
+        if (verbose)
+            printf(" " LIBXL_UUID_FMT, LIBXL_UUID_BYTES(info[i].uuid));
         putchar('\n');
     }
 }
@@ -2211,11 +2203,7 @@ void list_vm(void)
     printf("UUID                                  ID    name\n");
     for (i = 0; i < nb_vm; i++) {
         domname = libxl_domid_to_name(&ctx, info[i].domid);
-        printf(UUID_FMT "  %d    %-30s\n",
-            info[i].uuid[0], info[i].uuid[1], info[i].uuid[2], info[i].uuid[3],
-            info[i].uuid[4], info[i].uuid[5], info[i].uuid[6], info[i].uuid[7],
-            info[i].uuid[8], info[i].uuid[9], info[i].uuid[10], info[i].uuid[11],
-            info[i].uuid[12], info[i].uuid[13], info[i].uuid[14], info[i].uuid[15],
+        printf(LIBXL_UUID_FMT "  %d    %-30s\n", LIBXL_UUID_BYTES(info[i].uuid),
             info[i].domid, domname);
         free(domname);
     }