diff --git a/Source/Core/VideoCommon/Fifo.cpp b/Source/Core/VideoCommon/Fifo.cpp
index d71e3e47d2..de815012f7 100644
--- a/Source/Core/VideoCommon/Fifo.cpp
+++ b/Source/Core/VideoCommon/Fifo.cpp
@@ -424,7 +424,7 @@ void Fifo_UpdateWantDeterminism(bool want)
 	// We are paused (or not running at all yet) and have m_csHWVidOccupied, so
 	// it should be safe to change this.
 	const SCoreStartupParameter& param = SConfig::GetInstance().m_LocalCoreStartupParameter;
-	bool gpu_thread;
+	bool gpu_thread = false;
 	switch (param.m_GPUDeterminismMode)
 	{
 		case GPU_DETERMINISM_AUTO:
diff --git a/Source/Core/VideoCommon/RenderBase.cpp b/Source/Core/VideoCommon/RenderBase.cpp
index 0e5dbba3cf..ee31d50ff0 100644
--- a/Source/Core/VideoCommon/RenderBase.cpp
+++ b/Source/Core/VideoCommon/RenderBase.cpp
@@ -169,6 +169,7 @@ void Renderer::CalculateTargetScale(int x, int y, int &scaledX, int &scaledY)
 bool Renderer::CalculateTargetSize(unsigned int framebuffer_width, unsigned int framebuffer_height)
 {
 	int newEFBWidth, newEFBHeight;
+	newEFBWidth = newEFBHeight = 0;
 
 	// TODO: Ugly. Clean up
 	switch (s_LastEFBScale)