diff --git a/util/superiotool/Makefile b/util/superiotool/Makefile
index 6e86d01352..44d0316e5a 100644
--- a/util/superiotool/Makefile
+++ b/util/superiotool/Makefile
@@ -24,9 +24,9 @@ CC      = gcc
 INSTALL = /usr/bin/install
 PREFIX  = /usr/local
 
-# TODO: -ansi, -pedantic
+# TODO: -pedantic
 CFLAGS = -O2 -Wall -Werror -Wstrict-prototypes -Wundef -Wstrict-aliasing \
-         -Werror-implicit-function-declaration
+         -Werror-implicit-function-declaration -ansi
 
 OBJS = superiotool.o fintek.o ite.o nsc.o smsc.o
 
diff --git a/util/superiotool/fintek.c b/util/superiotool/fintek.c
index f7baaf6989..c12954c7f9 100644
--- a/util/superiotool/fintek.c
+++ b/util/superiotool/fintek.c
@@ -20,7 +20,7 @@
 
 #include "superiotool.h"
 
-void dump_fintek(unsigned short port, unsigned int did)
+void dump_fintek(uint16_t port, uint16_t did)
 {
 	switch (did) {
 	case 0x0604:
@@ -89,9 +89,9 @@ void dump_fintek(unsigned short port, unsigned int did)
 	       regval(port, 0xf6), regval(port, 0xf7), regval(port, 0xf8));
 }
 
-void probe_idregs_fintek(unsigned short port)
+void probe_idregs_fintek(uint16_t port)
 {
-	unsigned int vid, did, success = 0;
+	uint16_t vid, did, success = 0;
 
 	/* Enable configuration sequence (Fintek uses this for example)
 	 * Older ITE chips have the same enable sequence.
diff --git a/util/superiotool/ite.c b/util/superiotool/ite.c
index 41f2a9bb3d..938613efd4 100644
--- a/util/superiotool/ite.c
+++ b/util/superiotool/ite.c
@@ -187,7 +187,7 @@ const static struct superio_registers reg_table[] = {
 	{EOT}
 };
 
-void dump_ite(unsigned short port, unsigned short id)
+void dump_ite(uint16_t port, uint16_t id)
 {
 	int i;
 
@@ -211,9 +211,9 @@ void dump_ite(unsigned short port, unsigned short id)
 	}
 }
 
-void probe_idregs_ite(unsigned short port)
+void probe_idregs_ite(uint16_t port)
 {
-	unsigned int id, chipver;
+	uint16_t id, chipver;
 
 	/* Enable configuration sequence (ITE uses this for newer IT87[012]x)
 	 * IT871[01] uses 0x87, 0x87 -> fintek detection should handle it
diff --git a/util/superiotool/nsc.c b/util/superiotool/nsc.c
index 0fb2b7463e..691ce13967 100644
--- a/util/superiotool/nsc.c
+++ b/util/superiotool/nsc.c
@@ -25,7 +25,7 @@ static const char *familyid[] = {
 	[0xf1] = "PC8374 (Winbond/NatSemi)"
 };
 
-void dump_ns8374(unsigned short port)
+void dump_ns8374(uint16_t port)
 {
 	printf("Enables: 21=%02x, 22=%02x, 23=%02x, 24=%02x, 26=%02x\n",
 	       regval(port, 0x21), regval(port, 0x22), regval(port, 0x23),
@@ -56,9 +56,9 @@ void dump_ns8374(unsigned short port)
 	     regval(port, 0xf0));
 }
 
-void probe_idregs_simple(unsigned short port)
+void probe_idregs_simple(uint16_t port)
 {
-	unsigned char id;
+	uint16_t id;
 
 	outb(0x20, port);
 	if (inb(port) != 0x20) {
diff --git a/util/superiotool/smsc.c b/util/superiotool/smsc.c
index f836b94a99..7636001bc1 100644
--- a/util/superiotool/smsc.c
+++ b/util/superiotool/smsc.c
@@ -41,7 +41,7 @@ const static struct superio_registers reg_table[] = {
 };
 
 /* Note: The actual SMSC ID is 16 bits, but we must pass 32 bits here. */
-void dump_smsc(uint32_t port, uint32_t id)
+void dump_smsc(uint16_t port, uint16_t id)
 {
 	switch (id) {
 	case 0x28:
@@ -53,7 +53,7 @@ void dump_smsc(uint32_t port, uint32_t id)
 	}
 }
 
-void probe_idregs_smsc(unsigned short port)
+void probe_idregs_smsc(uint16_t port)
 {
 	uint16_t id, rev;
 
diff --git a/util/superiotool/superiotool.c b/util/superiotool/superiotool.c
index 3514b24415..e95f1baac6 100644
--- a/util/superiotool/superiotool.c
+++ b/util/superiotool/superiotool.c
@@ -22,23 +22,23 @@
 
 #include "superiotool.h"
 
-unsigned char regval(unsigned short port, unsigned char reg)
+uint8_t regval(uint16_t port, uint8_t reg)
 {
 	outb(reg, port);
 	return inb(port + 1);
 }
 
-void regwrite(unsigned short port, unsigned char reg, unsigned char val)
+void regwrite(uint16_t port, uint8_t reg, uint8_t val)
 {
 	outb(reg, port);
 	outb(val, port + 1);
 }
 
 void dump_superio(const char *name, const struct superio_registers reg_table[],
-		  unsigned short port, unsigned short id)
+		  uint16_t port, uint16_t id)
 {
 	int i, j, k;
-	signed short *idx;
+	int *idx;
 
 	printf("%s ", name);
 
@@ -46,33 +46,32 @@ void dump_superio(const char *name, const struct superio_registers reg_table[],
 		if (reg_table[i].superio_id == EOT)
 			break;
 
-		if ((unsigned short)reg_table[i].superio_id != id)
+		if ((uint16_t)reg_table[i].superio_id != id)
 			continue;
 
 		printf("%s\n", reg_table[i].name);
 
-		for (j = 0;; j++) {
+		for (j = 0; /* Nothing */; j++) {
 			if (reg_table[i].ldn[j].ldn == EOT)
 				break;
 
 			if (reg_table[i].ldn[j].ldn != NOLDN) {
-				printf("Switching to LDN 0x%01x\n",
+				printf("Switching to LDN 0x%02x\n",
 				       reg_table[i].ldn[j].ldn);
-				regwrite(port, 0x07,
-					 reg_table[i].ldn[j].ldn);
+				regwrite(port, 0x07, reg_table[i].ldn[j].ldn);
 			}
 
 			idx = reg_table[i].ldn[j].idx;
 
 			printf("idx ");
-			for (k = 0;; k++) {
+			for (k = 0; /* Nothing */; k++) {
 				if (idx[k] == EOT)
 					break;
 				printf("%02x ", idx[k]);
 			}
 
 			printf("\nval ");
-			for (k = 0;; k++) {
+			for (k = 0; /* Nothing */; k++) {
 				if (idx[k] == EOT)
 					break;
 				printf("%02x ", regval(port, idx[k]));
@@ -80,7 +79,7 @@ void dump_superio(const char *name, const struct superio_registers reg_table[],
 
 			printf("\ndef ");
 			idx = reg_table[i].ldn[j].def;
-			for (k = 0;; k++) {
+			for (k = 0; /* Nothing */; k++) {
 				if (idx[k] == EOT)
 					break;
 				else if (idx[k] == NANA)
diff --git a/util/superiotool/superiotool.h b/util/superiotool/superiotool.h
index 4986ff167c..f4b2a85935 100644
--- a/util/superiotool/superiotool.h
+++ b/util/superiotool/superiotool.h
@@ -41,43 +41,42 @@
 #define MAXNUMPORTS	(2 + 1)		/* Maximum number of Super I/O ports */
 
 struct superio_registers {
-	/* Yes, superio_id should be unsigned, but EOT has to be negative. */
-	signed short superio_id;
+	int32_t superio_id; /* Signed, as we need EOT. */
 	const char name[MAXNAMELEN];
 	struct {
-		signed short ldn;
-		signed short idx[IDXSIZE];
-		signed short def[IDXSIZE];
+		int ldn;
+		int idx[IDXSIZE];
+		int def[IDXSIZE];
 	} ldn[LDNSIZE];
 };
 
 /* superiotool.c */
-unsigned char regval(unsigned short port, unsigned char reg);
-void regwrite(unsigned short port, unsigned char reg, unsigned char val);
+uint8_t regval(uint16_t port, uint8_t reg);
+void regwrite(uint16_t port, uint8_t reg, uint8_t val);
 void dump_superio(const char *name, const struct superio_registers reg_table[],
-                  unsigned short port, unsigned short id);
-void probe_superio(unsigned short port);
+                  uint16_t port, uint16_t id);
+void probe_superio(uint16_t port);
 
 /* fintek.c */
-void dump_fintek(unsigned short port, unsigned int did);
-void probe_idregs_fintek(unsigned short port);
+void dump_fintek(uint16_t port, uint16_t did);
+void probe_idregs_fintek(uint16_t port);
 
 /* ite.c */
-void dump_ite(unsigned short port, unsigned short id);
-void probe_idregs_ite(unsigned short port);
+void dump_ite(uint16_t port, uint16_t id);
+void probe_idregs_ite(uint16_t port);
 
 /* nsc.c */
-void dump_ns8374(unsigned short port);
-void probe_idregs_simple(unsigned short port);
+void dump_ns8374(uint16_t port);
+void probe_idregs_simple(uint16_t port);
 
 /* smsc.c */
-void dump_smsc(uint32_t port, uint32_t id);
-void probe_idregs_smsc(unsigned short port);
+void dump_smsc(uint16_t port, uint16_t id);
+void probe_idregs_smsc(uint16_t port);
 
 /** Table of which config ports to probe on each Super I/O. */
 const static struct {
-	void (*probe_idregs) (unsigned short port);
-	signed short ports[MAXNUMPORTS]; /* Signed, as we need EOT. */
+	void (*probe_idregs) (uint16_t port);
+	int ports[MAXNUMPORTS]; /* Signed, as we need EOT. */
 } superio_ports_table[] = {
 	{probe_idregs_simple,	{0x2e,	0x4e,	EOT}},
 	{probe_idregs_fintek,	{0x2e,	0x4e,	EOT}},