diff --git a/src/lgfx/utility/lgfx_tjpgd.c b/src/lgfx/utility/lgfx_tjpgd.c
index 0b07d1d9..15bd33c9 100644
--- a/src/lgfx/utility/lgfx_tjpgd.c
+++ b/src/lgfx/utility/lgfx_tjpgd.c
@@ -130,7 +130,7 @@ static inline int32_t BYTECLIP (
 /*---------------------------------------------*/
 
 #if JD_BAYER
-static const int_fast8_t Bayer[16] = { 0, 4, 1, 5,-2, 2,-1, 3, 1, 5, 0, 4,-1, 3,-2, 2};
+static const int8_t Bayer[16] = { 0, 4, 1, 5,-2, 2,-1, 3, 1, 5, 0, 4,-1, 3,-2, 2};
 #endif
 
 
@@ -299,7 +299,7 @@ static int32_t huffext (	/* >=0: decoded data, <0: error code */
 {
 	const uint8_t* hb_end = hb + 16 + 1;
 	uint_fast8_t msk = jd->dbit;
-	uint_fast16_t w = *jd->dptr & ((1ul << msk) - 1);
+	uint32_t w = *jd->dptr & ((1ul << msk) - 1);
 	for (;;) {
 		if (!msk) {				/* Next byte? */
 			uint8_t *dp = jd->dptr;
@@ -584,7 +584,7 @@ static JRESULT mcu_output (
 		iy = 0;
 		do {
 #if JD_BAYER
-			const int_fast8_t* btbl = &Bayer[(iy & 3) << 2];
+			const int8_t* btbl = &Bayer[(iy & 3) << 2];
 #endif
 			py = &jd->mcubuf[((iy & 8) + iy) << 3];
 			pc = &jd->mcubuf[((mx << iyshift) + (iy >> iyshift)) << 3];
@@ -596,10 +596,10 @@ static JRESULT mcu_output (
 					++pc;
 
 				/* Convert CbCr to RGB */
-					uint_fast16_t rr = ((int32_t)(1.402   * (1<<FP_SHIFT)) * cr) >> FP_SHIFT;
-					uint_fast16_t gg = ((int32_t)(0.34414 * (1<<FP_SHIFT)) * cb
+					int32_t rr = ((int32_t)(1.402   * (1<<FP_SHIFT)) * cr) >> FP_SHIFT;
+					int32_t gg = ((int32_t)(0.34414 * (1<<FP_SHIFT)) * cb
 									  + (int32_t)(0.71414 * (1<<FP_SHIFT)) * cr) >> FP_SHIFT;
-					uint_fast16_t bb = ((int32_t)(1.772   * (1<<FP_SHIFT)) * cb) >> FP_SHIFT;
+					int32_t bb = ((int32_t)(1.772   * (1<<FP_SHIFT)) * cb) >> FP_SHIFT;
 					do {
 #if JD_BAYER
 						yy = *py + btbl[ix & 3];		/* Get Y component */
diff --git a/src/lgfx/utility/lgfx_tjpgd.h b/src/lgfx/utility/lgfx_tjpgd.h
index e8ecb23e..e4523b38 100644
--- a/src/lgfx/utility/lgfx_tjpgd.h
+++ b/src/lgfx/utility/lgfx_tjpgd.h
@@ -63,13 +63,13 @@ struct lgfxJdec {
 	uint8_t* dptr;				/* Current data read ptr */
 	uint8_t* dpend;				/* data end ptr */
 	uint8_t* inbuf;				/* Bit stream input buffer */
-	uint_fast8_t dbit;			/* Current bit in the current read byte */
-	uint_fast8_t scale;			/* Output scaling ratio */
-	uint_fast8_t msx, msy;		/* MCU size in unit of block (width, height) */
-	uint_fast8_t qtid[3];		/* Quantization table ID of each component */
+	uint8_t dbit;			/* Current bit in the current read byte */
+	uint8_t scale;			/* Output scaling ratio */
+	uint8_t msx, msy;		/* MCU size in unit of block (width, height) */
+	uint8_t qtid[3];		/* Quantization table ID of each component */
 	int32_t dcv[3];				/* Previous DC element of each component */
 	uint16_t nrst;				/* Restart inverval */
-	uint_fast16_t width, height;/* Size of the input image (pixel) */
+	uint16_t width, height;/* Size of the input image (pixel) */
 	uint8_t* huffbits[2][2];	/* Huffman bit distribution tables [id][dcac] */
 	uint16_t* huffcode[2][2];	/* Huffman code word tables [id][dcac] */
 	uint8_t* huffdata[2][2];	/* Huffman decoded data tables [id][dcac] */
@@ -77,7 +77,7 @@ struct lgfxJdec {
 	void* workbuf;				/* Working buffer for IDCT and RGB output */
 	int16_t* mcubuf;			/* Working buffer for the MCU */
 	uint8_t* pool;				/* Pointer to available memory pool */
-	uint_fast16_t sz_pool;			/* Size of momory pool (bytes available) */
+	uint16_t sz_pool;			/* Size of momory pool (bytes available) */
 	uint32_t (*infunc)(void*, uint8_t*, uint32_t);/* Pointer to jpeg stream input function */
 	void* device;				/* Pointer to I/O device identifiler for the session */
 	uint8_t comps_in_frame;		/* 1=Y(grayscale)  3=YCrCb */