diff --git a/clash-vexriscv/src/VexRiscv.hs b/clash-vexriscv/src/VexRiscv.hs
index 09e318c..4ce50f2 100644
--- a/clash-vexriscv/src/VexRiscv.hs
+++ b/clash-vexriscv/src/VexRiscv.hs
@@ -70,7 +70,7 @@ data CpuOut = CpuOut
   }
   deriving (Generic, NFDataX, ShowX, Eq, BitPack)
 
-data DumpVcd = DumpVcd FilePath | NoDumpVcd
+data DumpVcd = DumpVcd { vcdPath :: FilePath, vcdLevels :: Int }  | NoDumpVcd
 
 
 data Jtag (dom :: Domain)
@@ -532,9 +532,9 @@ vexCPU dumpVcd = do
   v <- vexrInit
   vcd <- case dumpVcd of
     NoDumpVcd -> pure nullPtr
-    DumpVcd path -> do
+    DumpVcd path levels -> do
       vcdPath <- newCString path
-      vexrInitVcd v vcdPath
+      vexrInitVcd v vcdPath levels
 
   let
     {-# NOINLINE initStage1 #-}
diff --git a/clash-vexriscv/src/VexRiscv/FFI.hsc b/clash-vexriscv/src/VexRiscv/FFI.hsc
index c466c1f..1090a48 100644
--- a/clash-vexriscv/src/VexRiscv/FFI.hsc
+++ b/clash-vexriscv/src/VexRiscv/FFI.hsc
@@ -24,7 +24,7 @@ data VerilatedVcdC
 data VexRiscvJtagBridge
 
 foreign import ccall unsafe "vexr_init" vexrInit :: IO (Ptr VexRiscv)
-foreign import ccall unsafe "vexr_init_vcd" vexrInitVcd :: Ptr VexRiscv -> CString -> IO (Ptr VerilatedVcdC)
+foreign import ccall unsafe "vexr_init_vcd" vexrInitVcd :: Ptr VexRiscv -> CString -> Int -> IO (Ptr VerilatedVcdC)
 foreign import ccall unsafe "vexr_shutdown" vexrShutdown :: Ptr VexRiscv -> IO ()
 
 foreign import ccall unsafe "vexr_init_stage1" vexrInitStage1 :: Ptr VerilatedVcdC -> Ptr VexRiscv -> Ptr NON_COMB_INPUT -> Ptr OUTPUT -> IO ()
diff --git a/clash-vexriscv/src/ffi/impl.cpp b/clash-vexriscv/src/ffi/impl.cpp
index 3288345..c7a6239 100644
--- a/clash-vexriscv/src/ffi/impl.cpp
+++ b/clash-vexriscv/src/ffi/impl.cpp
@@ -32,7 +32,7 @@ typedef struct {
 
 extern "C" {
 VVexRiscv *vexr_init();
-VerilatedVcdC *vexr_init_vcd(VVexRiscv *top, const char *path);
+VerilatedVcdC *vexr_init_vcd(VVexRiscv *top, const char *path, int levels);
 void vexr_shutdown(VVexRiscv *top);
 
 void vexr_init_stage1(VerilatedVcdC *vcd, VVexRiscv *top,
@@ -61,12 +61,10 @@ VVexRiscv *vexr_init() {
   return v;
 }
 
-VerilatedVcdC *vexr_init_vcd(VVexRiscv *top, const char *path) {
+VerilatedVcdC *vexr_init_vcd(VVexRiscv *top, const char *path, int levels) {
   VerilatedVcdC *vcd = new VerilatedVcdC;
   Verilated::traceEverOn(true);
-  // Trace 99 levels of the hierarchy. We only have one level AFAIK, so this
-  // should be enough :-).
-  top->trace(vcd, 99);
+  top->trace(vcd, levels);
   vcd->open(path);
   return vcd;
 }