diff --git a/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp b/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
index 8dcd62831e..c565ee8d43 100644
--- a/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
@@ -610,8 +610,10 @@ void UpdateViewport()
 	
 	// This seems to happen a lot - the above calc is probably wrong.
 	if (vp.MinZ < 0.0f) vp.MinZ = 0.0f;
+	if (vp.MinZ > 1.0f) vp.MinZ = 1.0f;
 	if (vp.MaxZ > 1.0f) vp.MaxZ = 1.0f;
-	
+	if (vp.MaxZ < 0.0f) vp.MaxZ = 0.0f;
+
 	D3D::dev->SetViewport(&vp);
 }
 
diff --git a/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp b/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
index 43bb17a15d..0036b494b5 100644
--- a/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
@@ -1347,6 +1347,11 @@ void UpdateViewport()
 	double GLNear = (xfregs.rawViewport[5] - xfregs.rawViewport[2]) / 16777216.0f;
 	double GLFar = xfregs.rawViewport[5] / 16777216.0f;
 
+	if (GLNear < 0.0f) GLNear = 0.0f;
+	if (GLNear > 1.0f) GLNear = 1.0f;
+	if (GLFar > 1.0f) GLFar = 1.0f;
+	if (GLFar < 0.0f) GLFar = 0.0f;
+
 	// Update the view port
 	glViewport(GLx, GLy, GLWidth, GLHeight);
 	glDepthRange(GLNear, GLFar);