diff --git a/deps/CMakeLists.txt b/deps/CMakeLists.txt
index f312064f..4f4a6454 100644
--- a/deps/CMakeLists.txt
+++ b/deps/CMakeLists.txt
@@ -8,7 +8,7 @@ else ()
 
     FetchContent_Declare(tlsuv
             GIT_REPOSITORY https://github.com/openziti/tlsuv.git
-            GIT_TAG v0.27.2
+            GIT_TAG v0.26.1
             )
     FetchContent_MakeAvailable(tlsuv)
 
diff --git a/library/ziti_ctrl.c b/library/ziti_ctrl.c
index ea40e5e0..b591f09e 100644
--- a/library/ziti_ctrl.c
+++ b/library/ziti_ctrl.c
@@ -132,7 +132,7 @@ static void ctrl_paging_req(struct ctrl_resp *resp);
 
 static void ctrl_default_cb(void *s, const ziti_error *e, struct ctrl_resp *resp);
 
-static void ctrl_body_cb(tlsuv_http_req_t *req, char *b, ssize_t len);
+static void ctrl_body_cb(tlsuv_http_req_t *req, const char *b, ssize_t len);
 
 static tlsuv_http_req_t *
 start_request(tlsuv_http_t *http, const char *method, const char *path, tlsuv_http_resp_cb cb, struct ctrl_resp *resp) {
@@ -285,11 +285,11 @@ static void ctrl_service_cb(ziti_service **services, ziti_error *e, struct ctrl_
     free(services);
 }
 
-static void free_body_cb(tlsuv_http_req_t *req, char *body, ssize_t len) {
+static void free_body_cb(tlsuv_http_req_t *req, const char *body, ssize_t len) {
     free((char *) body);
 }
 
-static void ctrl_body_cb(tlsuv_http_req_t *req, char *b, ssize_t len) {
+static void ctrl_body_cb(tlsuv_http_req_t *req, const char *b, ssize_t len) {
     struct ctrl_resp *resp = req->data;
     ziti_controller *ctrl = resp->ctrl;
 
diff --git a/programs/sample_http_link/sample_http_link.c b/programs/sample_http_link/sample_http_link.c
index 77780345..0477a463 100644
--- a/programs/sample_http_link/sample_http_link.c
+++ b/programs/sample_http_link/sample_http_link.c
@@ -45,7 +45,7 @@ void resp_cb(tlsuv_http_resp_t *resp, void *data) {
     printf("\n");
 }
 
-void body_cb(tlsuv_http_req_t *req, char *body, ssize_t len) {
+void body_cb(tlsuv_http_req_t *req, const char *body, ssize_t len) {
     if (len == UV_EOF) {
         printf("\n\n====================\nRequest completed\n");
         ziti_shutdown(ziti);
diff --git a/tests/ziti_src_tests.cpp b/tests/ziti_src_tests.cpp
index 544befe2..a9b83e8c 100644
--- a/tests/ziti_src_tests.cpp
+++ b/tests/ziti_src_tests.cpp
@@ -60,7 +60,7 @@ TEST_CASE("httpbin.ziti:ziti_src", "[integ]") {
                     auto t = (source_test*)ctx;
                     t->code = resp->code;
 
-                    resp->body_cb = [](tlsuv_http_req_t *req, char *body, ssize_t len){
+                    resp->body_cb = [](tlsuv_http_req_t *req, const char *body, ssize_t len){
                         auto t = (source_test*)req->data;
                         if (len > 0)
                             t->body.append(body, len);
diff --git a/vcpkg.json b/vcpkg.json
index 1640392e..e4f00eac 100644
--- a/vcpkg.json
+++ b/vcpkg.json
@@ -28,5 +28,5 @@
       ]
     }
   },
-  "builtin-baseline": "8eb57355a4ffb410a2e94c07b4dca2dffbee8e50"
+  "builtin-baseline": "f6a5d4e8eb7476b8d7fc12a56dff300c1c986131"
 }