diff --git a/include/verilated_vpi.h b/include/verilated_vpi.h
index 3442fd204..f31484b0c 100644
--- a/include/verilated_vpi.h
+++ b/include/verilated_vpi.h
@@ -107,7 +107,7 @@ public:
     // cppcheck-suppress uninitVar  // m_value
     VerilatedVpioCb(const t_cb_data* cbDatap, QData time)
 	: m_cbData(*cbDatap), m_time(time) {
-        m_value.format = cbDatap->value?cbDatap->value->format:vpiSuppressVal;
+        m_value.format = cbDatap->value ? cbDatap->value->format : vpiSuppressVal;
 	m_cbData.value = &m_value;
     }
     virtual ~VerilatedVpioCb() {}
diff --git a/test_regress/t/t_vpi_var.cpp b/test_regress/t/t_vpi_var.cpp
index f5491c988..bbb7fa97b 100644
--- a/test_regress/t/t_vpi_var.cpp
+++ b/test_regress/t/t_vpi_var.cpp
@@ -125,6 +125,7 @@ int _mon_check_callbacks() {
     cb_data.reason = cbEndOfSimulation;
     cb_data.cb_rtn = NULL;
     cb_data.user_data = 0;
+    cb_data.value = NULL;
 
     vpiHandle vh = vpi_register_cb(&cb_data);
     CHECK_RESULT_NZ(vh);