diff --git a/test_c/sim_main.cpp b/test_c/sim_main.cpp
index a53851a6a..965bdadcc 100644
--- a/test_c/sim_main.cpp
+++ b/test_c/sim_main.cpp
@@ -39,7 +39,7 @@ int main(int argc, char **argv, char **env) {
     top->clk = 0;
     top->passed = 0;
 
-    while (main_time < 60 && !top->passed) {
+    while (main_time < 60 && !top->passed && !Verilated::gotFinish()) {
 
 	if ((main_time % 10) == 3) {	// Toggle clock
 	    top->clk = 1;
@@ -55,7 +55,7 @@ int main(int argc, char **argv, char **env) {
 
 	top->eval();		// Evaluate model
 #if VM_TRACE
-	tfp->dump (main_time);	// Create waveform trace for this timestamp
+	if (tfp) tfp->dump (main_time);	// Create waveform trace for this timestamp
 #endif
 
 	// Read outputs
@@ -70,7 +70,7 @@ int main(int argc, char **argv, char **env) {
     top->final();
 
 #if VM_TRACE
-    tfp->close();
+    if (tfp) tfp->close();
 #endif
 
     if (!top->passed) {
diff --git a/test_regress/driver.pl b/test_regress/driver.pl
index ba28eabd4..f87bbd786 100755
--- a/test_regress/driver.pl
+++ b/test_regress/driver.pl
@@ -807,7 +807,7 @@ sub _make_main {
 
     if ($self->{trace}) {
 	$fh->print("#if VM_TRACE\n");
-	$fh->print("	tfp->close();\n");
+	$fh->print("	if (tfp) tfp->close();\n");
 	$fh->print("#endif //VM_TRACE\n");
     }
     $fh->print("\n");
@@ -840,7 +840,7 @@ sub _print_advance_time {
 	    print $fh "	${set}eval();\n";
 	    if ($self->{trace} && !$self->{sp}) {
 		$fh->print("#if VM_TRACE\n");
-		$fh->print("	tfp->dump (main_time);\n");
+		$fh->print("	if (tfp) tfp->dump (main_time);\n");
 		$fh->print("#endif //VM_TRACE\n");
 	    }
 	}
diff --git a/test_sp/sc_main.cpp b/test_sp/sc_main.cpp
index 661a32d56..712e6d01c 100644
--- a/test_sp/sc_main.cpp
+++ b/test_sp/sc_main.cpp
@@ -134,11 +134,11 @@ int sc_main(int argc, char* argv[]) {
     cout <<("Test beginning...\n");
 
     reset_l = 1;
-    while (VL_TIME_Q() < 60 && !passed) {
+    while (VL_TIME_Q() < 60 && !passed && !Verilated::gotFinish()) {
 #if WAVES
 	// Flush the wave files each cycle so we can immediately see the output
 	// Don't do this in "real" programs, do it in a abort() handler instead
-	tfp->flush();
+	if (tfp) tfp->flush();
 #endif
 	if (VL_TIME_Q() > 10) {
 	    reset_l = 1;	// Deassert reset
@@ -157,7 +157,7 @@ int sc_main(int argc, char* argv[]) {
     //==========
     //  Close Waves
 #if WAVES
-    tfp->close();
+    if (tfp) tfp->close();
 #endif
 
     if (!passed) {