diff --git a/src/lib/sw_engine/tvgSwCommon.h b/src/lib/sw_engine/tvgSwCommon.h
index 6e78543f..be91cfab 100644
--- a/src/lib/sw_engine/tvgSwCommon.h
+++ b/src/lib/sw_engine/tvgSwCommon.h
@@ -279,7 +279,7 @@ static inline uint32_t COLOR_INTERPOLATE(uint32_t c1, uint32_t a1, uint32_t c2,
     return (c1 |= t);
 }
 
-static inline uint8_t ALPHA_MULTIPLY(uint32_t c, uint32_t a)
+static inline uint32_t ALPHA_MULTIPLY(uint32_t c, uint32_t a)
 {
     return ((c * a + 0xff) >> 8);
 }