diff --git a/src/api/graphics.c b/src/api/graphics.c
index 2661c80d..7abe7b66 100644
--- a/src/api/graphics.c
+++ b/src/api/graphics.c
@@ -764,10 +764,10 @@ static int l_lovrGraphicsPlane(lua_State* L) {
   }
   float transform[16];
   int index = luax_readmat4(L, 2, transform, 2);
-  float u = luax_optfloat(L, index, 0.f);
-  float v = luax_optfloat(L, index, 0.f);
-  float w = luax_optfloat(L, index, 1.f - u);
-  float h = luax_optfloat(L, index, 1.f - v);
+  float u = luax_optfloat(L, index++, 0.f);
+  float v = luax_optfloat(L, index++, 0.f);
+  float w = luax_optfloat(L, index++, 1.f - u);
+  float h = luax_optfloat(L, index++, 1.f - v);
   lovrGraphicsPlane(style, material, transform, u, v, w, h);
   return 0;
 }