diff --git a/util/dtc/dtc.h b/util/dtc/dtc.h
index 43aad55297..e1142cd4eb 100644
--- a/util/dtc/dtc.h
+++ b/util/dtc/dtc.h
@@ -86,8 +86,8 @@ typedef u32 cell_t;
 #define be64_to_cpu(x)	bswap_64(x)
 #endif
 
-#define streq(a, b)	(strcmp((a), (b)) == 0)
-#define strneq(a, b, n)	(strncmp((a), (b), (n)) == 0)
+#define streq(a, b)	(strcmp((char *)(a), (char *)(b)) == 0)
+#define strneq(a, b, n)	(strncmp((char *)(a), (char *)(b), (n)) == 0)
 
 #define ALIGN(x, a)	(((x) + (a) - 1) & ~((a) - 1))
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
diff --git a/util/dtc/flattree.c b/util/dtc/flattree.c
index fe214aafe0..f28a5168f6 100644
--- a/util/dtc/flattree.c
+++ b/util/dtc/flattree.c
@@ -532,22 +532,22 @@ static void linuxbios_emit_special(FILE *e, struct node *tree)
 		}
 
 		if (streq(prop->name, "ops")){
-			fprintf(f, "\t.ops = &%s,\n", clean(prop->val.val, 0));
+			fprintf(f, "\t.ops = &%s,\n", clean((char *)prop->val.val, 0));
 			ops_set  = 1;
 		}
 
 		if (streq(prop->name, "ops_pci")){
-			fprintf(f, "\t.ops_pci = &%s,\n", clean(prop->val.val, 0));
+			fprintf(f, "\t.ops_pci = &%s,\n", clean((char *)prop->val.val, 0));
 			ops_set  = 1;
 		}
 
 		if (streq(prop->name, "ops_pci_bus")){
-			fprintf(f, "\t.ops_pci_bus = &%s,\n", clean(prop->val.val, 0));
+			fprintf(f, "\t.ops_pci_bus = &%s,\n", clean((char *)prop->val.val, 0));
 			ops_set  = 1;
 		}
 
 		if (streq(prop->name, "ops_smbus_bus")){
-			fprintf(f, "\t.ops_smbus_bus = &%s,\n", clean(prop->val.val, 0));
+			fprintf(f, "\t.ops_smbus_bus = &%s,\n", clean((char *)prop->val.val, 0));
 			ops_set  = 1;
 		}
 	}
@@ -895,7 +895,7 @@ static void dump_stringtable_asm(FILE *f, struct data strbuf)
 	p = strbuf.val;
 
 	while (p < (strbuf.val + strbuf.len)) {
-		len = strlen(p);
+		len = strlen((char *)p);
 		fprintf(f, "\t.string \"%s\"\n", p);
 		p += len+1;
 	}
@@ -996,7 +996,7 @@ static void dump_stringtable_C(FILE *f, struct data strbuf)
 
 	fprintf(f, "\tchar *stringtable[] = {\n");
 	while (p < (strbuf.val + strbuf.len)) {
-		len = strlen(p);
+		len = strlen((char *)p);
 		fprintf(f, "\t\"%s\"\n", p);
 		p += len+1;
 	}
diff --git a/util/options/build_opt_tbl.c b/util/options/build_opt_tbl.c
index b5dd2b931d..ee48cba108 100644
--- a/util/options/build_opt_tbl.c
+++ b/util/options/build_opt_tbl.c
@@ -183,7 +183,7 @@ static int is_ident_nondigit(int c)
 	return result;
 }
 
-static int is_ident(char *str)
+static int is_ident(unsigned char *str)
 {
 	int result;
 	int ch;
@@ -223,7 +223,7 @@ int main(int argc, char **argv)
 	struct cmos_entries *ce;
 	struct cmos_enums *c_enums, *c_enums_start;
 	struct cmos_checksum *cs;
-	unsigned char line[INPUT_LINE_MAX];
+	char line[INPUT_LINE_MAX];
 	unsigned char uc;
 	int entry_mode=0;
 	int enum_mode=0;
@@ -235,7 +235,7 @@ int main(int argc, char **argv)
 	int entries_length;
 	int enum_length;
 	int len;
-	unsigned char buf[16];
+	char buf[16];
 
         for(i=1;i<argc;i++) {
                 if(argv[i][0]!='-') {
@@ -347,7 +347,7 @@ int main(int argc, char **argv)
 		/* put in the record type */
 		ce->tag=LB_TAG_OPTION;
 		/* calculate and save the record length */
-		len=strlen(ce->name)+1;
+		len=strlen((char *)ce->name)+1;
 		/* make the record int aligned */
 		if(len%4)
 			len+=(4-(len%4));