diff --git a/sysdeps/unix/sysv/linux/alpha/bits/types.h b/sysdeps/unix/sysv/linux/alpha/bits/types.h
index 096d92050c..4bc43199d5 100644
--- a/sysdeps/unix/sysv/linux/alpha/bits/types.h
+++ b/sysdeps/unix/sysv/linux/alpha/bits/types.h
@@ -76,7 +76,7 @@ typedef struct
 typedef int __daddr_t;			/* Type of a disk address.  */
 typedef char *__caddr_t;		/* Type of a core address.  */
 typedef long int __time_t;
-typedef int __useconds_t;
+typedef unsigned int __useconds_t;
 typedef long int __suseconds_t;
 typedef long int __swblk_t;		/* Type of a swap block maybe?  */
 typedef long int __clock_t;
diff --git a/sysdeps/unix/sysv/linux/mips/bits/types.h b/sysdeps/unix/sysv/linux/mips/bits/types.h
index e1c436f319..d7176c31c6 100644
--- a/sysdeps/unix/sysv/linux/mips/bits/types.h
+++ b/sysdeps/unix/sysv/linux/mips/bits/types.h
@@ -81,8 +81,8 @@ typedef struct
 typedef int __daddr_t;			/* The type of a disk address.  */
 typedef char *__caddr_t;
 typedef long int __time_t;
+typedef unsigned int __useconds_t;
 typedef long int __suseconds_t;
-typedef int __useconds_t;
 typedef long int __swblk_t;		/* Type of a swap block maybe?  */
 
 typedef long int __clock_t;
diff --git a/sysdeps/unix/sysv/sysv4/solaris2/bits/types.h b/sysdeps/unix/sysv/sysv4/solaris2/bits/types.h
index ec1142c75f..79713e75ba 100644
--- a/sysdeps/unix/sysv/sysv4/solaris2/bits/types.h
+++ b/sysdeps/unix/sysv/sysv4/solaris2/bits/types.h
@@ -79,7 +79,7 @@ typedef unsigned int __id_t;	     /* General type for IDs.  */
 typedef long int __daddr_t;	     /* The type of a disk address.  */
 typedef char *__caddr_t;
 typedef long int __time_t;
-typedef int __useconds_t;
+typedef unsigned int __useconds_t;
 typedef int __suseconds_t;
 typedef long int __swblk_t;	     /* Type of a swap block maybe?  */
 typedef int __key_t;		     /* Type of an IPC key */