diff --git a/makefile b/makefile
index 5bb945a..970d35b 100644
--- a/makefile
+++ b/makefile
@@ -3,7 +3,6 @@ build:
 	@gcc main.c cmdbuf.c hex.c request.c response.c server.c pvbemu/core/vb.c \
 	-I include -I pvbemu/core \
 	-Werror -std=c90 -Wall -Wextra -Wpedantic \
-	-Wno-unused-parameter -Wno-unused-function \
 	-D _POSIX_C_SOURCE=199309L \
 	-o ./build/rdb
 clean:
diff --git a/pvbemu b/pvbemu
index d4ae5f3..5f563e6 160000
--- a/pvbemu
+++ b/pvbemu
@@ -1 +1 @@
-Subproject commit d4ae5f3909fa8f372ff70d11236cb38e4bd43732
+Subproject commit 5f563e6cac80d799f6c0251f9f601321e3603ea5
diff --git a/server.c b/server.c
index b17778c..24da6d3 100644
--- a/server.c
+++ b/server.c
@@ -69,11 +69,9 @@ const uint32_t SYSTEM_REGISTERS[] = {
 
 const uint32_t PC_INDEX = 32 + 13;
 
-/* TODO: this should use userdata */
-static void *SERVER_POINTER;
 static int onExecute(VB *sim, uint32_t address, const uint16_t *code, int length) {
     uint32_t i;
-    RdbServer *srv = SERVER_POINTER;
+    RdbServer *srv = (RdbServer *)vbGetUserData(sim);
 
     (void)sim;
     (void)code;
@@ -120,8 +118,8 @@ void rdbServerInit(RdbServer *srv, VB *sim) {
     srv->running = false;
     srv->brkslen = 0;
     srv->stopreason = stop_reason_none;
-    SERVER_POINTER = srv;
-    vbSetCallback(sim, VB_EXECUTE, (void*)(uint64_t)&onExecute);
+    vbSetUserData(sim, srv);
+    vbSetExecuteCallback(sim, onExecute);
 }
 
 int rdbServerHandleCommand(RdbServer *srv, CommandBuf *cmd, RdbResponse *res) {