diff --git a/SWTFT-Shield/SWTFT.cpp b/SWTFT-Shield/SWTFT.cpp
index 36967ea..f2a842b 100644
--- a/SWTFT-Shield/SWTFT.cpp
+++ b/SWTFT-Shield/SWTFT.cpp
@@ -18,6 +18,7 @@
 
 #define TFTWIDTH   240
 #define TFTHEIGHT  320
+#define swap(a, b) { int16_t t = a; a = b; b = t; }
 
 // Constructor for breakout board (configurable LCD control lines).
 // Can still use this w/shield, but parameters are ignored.