diff --git a/drivers/pci.c b/drivers/pci.c
index 2b4e525..f8c6414 100644
--- a/drivers/pci.c
+++ b/drivers/pci.c
@@ -297,7 +297,7 @@ ob_pci_encode_unit(int *idx)
 	case IO_SPACE:
 
 		/* [n]i[t]DD,F,RR,NNNNNNNN */
-        	snprintf(buf, sizeof(buf), "%si%s%x,%x,%x,%x",
+                snprintf(buf, sizeof(buf), "%si%s%x,%x,%x," FMT_ucellx,
 			 n ? "n" : "",	/* relocatable */
 			 t ? "t" : "",	/* aliased */
 			 dev, fn, reg, t ? lo & 0x03FF : lo);
@@ -306,7 +306,7 @@ ob_pci_encode_unit(int *idx)
 	case MEMORY_SPACE_32:
 
 		/* [n]m[t][p]DD,F,RR,NNNNNNNN */
-        	snprintf(buf, sizeof(buf), "%sm%s%s%x,%x,%x,%x",
+                snprintf(buf, sizeof(buf), "%sm%s%s%x,%x,%x," FMT_ucellx,
 			 n ? "n" : "",	/* relocatable */
 			 t ? "t" : "",	/* aliased */
 			 p ? "p" : "",	/* prefetchable */
@@ -319,7 +319,7 @@ ob_pci_encode_unit(int *idx)
         	snprintf(buf, sizeof(buf), "%sx%s%x,%x,%x,%llx",
 			 n ? "n" : "",	/* relocatable */
 			 p ? "p" : "",	/* prefetchable */
-			 dev, fn, reg, ((uint64_t)mid << 32) | (uint64_t)lo );
+                         dev, fn, reg, ((long long)mid << 32) | (long long)lo);
 		break;
 	}
 	push_str(buf);
diff --git a/fs/hfs/hfs_fs.c b/fs/hfs/hfs_fs.c
index 731ccab..293dc18 100644
--- a/fs/hfs/hfs_fs.c
+++ b/fs/hfs/hfs_fs.c
@@ -524,7 +524,7 @@ hfs_files_dir( hfs_info_t *dummy )
 
 	forth_printf("\n");
 	while( !hfs_readdir(common->dir, &ent) ) {
-		forth_printf("% 10d ", ent.u.file.dsize);
+                forth_printf("% 10ld ", ent.u.file.dsize);
 		print_date(ent.mddate);
 		if( ent.flags & HFS_ISDIR )
 			forth_printf("%s\\\n", ent.name);
diff --git a/include/libc/vsprintf.h b/include/libc/vsprintf.h
index e53c19f..4852274 100644
--- a/include/libc/vsprintf.h
+++ b/include/libc/vsprintf.h
@@ -20,11 +20,16 @@
 #include <stdarg.h>
 #include "config.h"
 
-extern int	vsprintf(char *buf, const char *fmt, va_list args );
-extern int	sprintf(char * buf, const char *fmt, ...);
-extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
-extern int snprintf(char * buf, size_t size, const char *fmt, ...);
+int vsprintf(char *buf, const char *fmt, va_list args)
+    __attribute__((__format__(__printf__, 2, 0)));
+int sprintf(char * buf, const char *fmt, ...)
+    __attribute__((__format__(__printf__, 2, 3)));
+int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
+    __attribute__((__format__(__printf__, 3, 0)));
+int snprintf(char * buf, size_t size, const char *fmt, ...)
+    __attribute__((__format__(__printf__, 3, 4)));
 
-extern int forth_printf( const char *fmt, ... );
+int forth_printf(const char *fmt, ...)
+    __attribute__((__format__(__printf__, 1, 2)));
 
 #endif   /* _H_VSPRINTF */