diff --git a/src/test/cpp/briey/main.cpp b/src/test/cpp/briey/main.cpp
index 0ee7c45..d2b372c 100644
--- a/src/test/cpp/briey/main.cpp
+++ b/src/test/cpp/briey/main.cpp
@@ -6,7 +6,6 @@
 #include "VBriey_RiscvCore.h"
 #endif
 #include "verilated.h"
-#include "verilated_vcd_c.h"
 #include <stdio.h>
 #include <iostream>
 #include <stdlib.h>
diff --git a/src/test/cpp/briey/makefile b/src/test/cpp/briey/makefile
index 12d4c97..e0a024b 100644
--- a/src/test/cpp/briey/makefile
+++ b/src/test/cpp/briey/makefile
@@ -13,7 +13,7 @@ ADDCFLAGS += -LDFLAGS -lSDL2
 
 ifeq ($(TRACE),yes)
 	VERILATOR_ARGS += --trace
-	ADDCFLAGS += -CFLAGS -DTRACE
+	ADDCFLAGS += -CFLAGS -DTRACE --trace-fst
 endif
 ifeq ($(DEBUG),yes)
 	ADDCFLAGS += -CFLAGS "-g3 -O0"
diff --git a/src/test/cpp/briey/makefile~ b/src/test/cpp/briey/makefile~
deleted file mode 100644
index b8345fd..0000000
--- a/src/test/cpp/briey/makefile~
+++ /dev/null
@@ -1,38 +0,0 @@
-DEBUG?=no
-TRACE?=no
-PRINT_PERF?=no
-TRACE_START=0
-ADDCFLAGS += -CFLAGS -pthread 
-
-ifeq ($(TRACE),yes)
-	VERILATOR_ARGS += --trace
-	ADDCFLAGS += -CFLAGS -DTRACE
-endif
-ifeq ($(DEBUG),yes)
-	ADDCFLAGS += -CFLAGS "-g3 -O0"
-endif
-ifneq ($(DEBUG),yes)
-	ADDCFLAGS += -CFLAGS "-O3"
-endif
-ifeq ($(PRINT_PERF),yes)
-	ADDCFLAGS += -CFLAGS -DPRINT_PERF
-endif
-
-ADDCFLAGS += -CFLAGS -DTRACE_START=${TRACE_START}
-
-
-
-all: clean compile
-
-run: compile
-	./obj_dir/VBriey
-
-verilate:
-	verilator -cc  ../../../../Briey.v -CFLAGS -std=c++11  ${ADDCFLAGS} --gdbbt ${VERILATOR_ARGS} -Wno-WIDTH --x-assign unique --exe main.cpp
- 	
-compile: verilate
-	make  -j  -C obj_dir/ -f VBriey.mk VBriey
- 	
-clean:
-	rm -rf obj_dir
- 	
diff --git a/src/test/cpp/common/framework.h b/src/test/cpp/common/framework.h
index 562d467..42c1f34 100644
--- a/src/test/cpp/common/framework.h
+++ b/src/test/cpp/common/framework.h
@@ -11,6 +11,7 @@
 #include <iomanip>
 #include <time.h>
 #include <unistd.h>
+#include "verilated_fst_c.h"
 
 using namespace std;
 
@@ -140,7 +141,7 @@ public:
 	string name;
 	uint64_t time = 0;
 	#ifdef TRACE
-	VerilatedVcdC* tfp;
+	VerilatedFstC* tfp;
 	#endif
 
 	ofstream logTraces;
@@ -184,9 +185,9 @@ public:
 		// init trace dump
 		#ifdef TRACE
 		Verilated::traceEverOn(true);
-		tfp = new VerilatedVcdC;
+		tfp = new VerilatedFstC;
 		top->trace(tfp, 99);
-		tfp->open((string(name)+ ".vcd").c_str());
+		tfp->open((string(name)+ ".fst").c_str());
 		#endif
 
 		struct timespec start_time,tick_time;
diff --git a/src/test/cpp/murax/makefile b/src/test/cpp/murax/makefile
index 71a5cd6..7c946ae 100644
--- a/src/test/cpp/murax/makefile
+++ b/src/test/cpp/murax/makefile
@@ -7,7 +7,7 @@ ADDCFLAGS += -CFLAGS -pthread -LDFLAGS -pthread
 
 ifeq ($(TRACE),yes)
 	VERILATOR_ARGS += --trace
-	ADDCFLAGS += -CFLAGS -DTRACE
+	ADDCFLAGS += -CFLAGS -DTRACE --trace-fst
 endif
 ifeq ($(DEBUG),yes)
 	ADDCFLAGS += -CFLAGS "-g3 -O0"