diff --git a/vvp/schedule.cc b/vvp/schedule.cc
index 933d6f668..a844727ed 100644
--- a/vvp/schedule.cc
+++ b/vvp/schedule.cc
@@ -565,7 +565,8 @@ static vvp_time64_t schedule_time;
 vvp_time64_t schedule_simtime(void)
 { return schedule_time; }
 
-extern void vpiPresim();
+extern void vpiEndOfCompile();
+extern void vpiStartOfSim();
 extern void vpiPostsim();
 extern void vpiNextSimTime(void);
 
@@ -600,8 +601,8 @@ void schedule_simulate(void)
 {
       schedule_time = 0;
 
-      // Execute pre-simulation callbacks
-      vpiPresim();
+      // Execute end of compile callbacks
+      vpiEndOfCompile();
 
 	// Execute initialization events.
       while (schedule_init_list) {
@@ -612,6 +613,9 @@ void schedule_simulate(void)
 	    delete cur;
       }
 
+      // Execute start of simulation callbacks
+      vpiStartOfSim();
+
       signals_capture();
 
       while (sched_list) {
diff --git a/vvp/vpi_callback.cc b/vvp/vpi_callback.cc
index 1af0b0f9f..7f7dccbd7 100644
--- a/vvp/vpi_callback.cc
+++ b/vvp/vpi_callback.cc
@@ -286,7 +286,7 @@ static struct __vpiCallback*EndOfCompile = NULL;
 static struct __vpiCallback*StartOfSimulation = NULL;
 static struct __vpiCallback*EndOfSimulation = NULL;
 
-void vpiPresim(void) {
+void vpiEndOfCompile(void) {
       struct __vpiCallback* cur;
 
       /*
@@ -303,6 +303,19 @@ void vpiPresim(void) {
 	    delete_vpi_callback(cur);
       }
 
+      vpi_mode_flag = VPI_MODE_NONE;
+}
+
+void vpiStartOfSim(void) {
+      struct __vpiCallback* cur;
+
+      /*
+       * Walk the list of register callbacks, executing them and
+       * freeing them when done.
+       */
+      assert(vpi_mode_flag == VPI_MODE_NONE);
+      vpi_mode_flag = VPI_MODE_RWSYNC;
+
       while (StartOfSimulation) {
 	    cur = StartOfSimulation;
 	    StartOfSimulation = cur->next;