diff --git a/rpcs3/rpcs3qt/debugger_frame.cpp b/rpcs3/rpcs3qt/debugger_frame.cpp
index 8bd80b7a77..8a9e1330c8 100644
--- a/rpcs3/rpcs3qt/debugger_frame.cpp
+++ b/rpcs3/rpcs3qt/debugger_frame.cpp
@@ -420,11 +420,9 @@ void debugger_frame::UpdateUnitList()
 		return;
 	}
 
+	const int old_size = m_choice_units->count();
 	QVariant old_cpu = m_choice_units->currentData();
 
-	m_choice_units->clear();
-	m_choice_units->addItem(NoThreadString);
-
 	const auto on_select = [&](u32 id, cpu_thread& cpu)
 	{
 		QVariant var_cpu = QVariant::fromValue<std::weak_ptr<cpu_thread>>(
@@ -437,8 +435,17 @@ void debugger_frame::UpdateUnitList()
 	{
 		const QSignalBlocker blocker(m_choice_units);
 
+		m_choice_units->clear();
+		m_choice_units->addItem(NoThreadString);
+
 		idm::select<named_thread<ppu_thread>>(on_select);
 		idm::select<named_thread<spu_thread>>(on_select);
+
+		if (m_choice_units->count() > 1 && old_size <= 1)
+		{
+			// Select the first thread after "No Thread", usually the PPU main thread
+			m_choice_units->setCurrentIndex(1);
+		}
 	}
 
 	OnSelectUnit();
diff --git a/rpcs3/rpcs3qt/debugger_frame.h b/rpcs3/rpcs3qt/debugger_frame.h
index 317ea23883..5f73d2e266 100644
--- a/rpcs3/rpcs3qt/debugger_frame.h
+++ b/rpcs3/rpcs3qt/debugger_frame.h
@@ -39,8 +39,8 @@ class debugger_frame : public custom_dock_widget
 	QTimer* m_update;
 	QSplitter* m_splitter;
 
-	u64 m_threads_created = 0;
-	u64 m_threads_deleted = 0;
+	u64 m_threads_created = -1;
+	u64 m_threads_deleted = -1;
 	u32 m_last_pc = -1;
 	std::vector<char> m_last_query_state;
 	u32 m_last_step_over_breakpoint = -1;