diff --git a/newlib/libc/machine/powerpc/vfprintf.c b/newlib/libc/machine/powerpc/vfprintf.c
index d264e26..e68b5ed 100644
--- a/newlib/libc/machine/powerpc/vfprintf.c
+++ b/newlib/libc/machine/powerpc/vfprintf.c
@@ -380,7 +380,7 @@ _DEFUN (_VFPRINTF_R, (data, fp, fmt0, ap),
 	int size;		/* size of converted field or string */
 	char *xdigs = NULL;	/* digits for [xX] conversion */
 #define NIOV 8
-	struct __suio uio;	/* output information: summary */
+	struct __suio uio = {0, 0, 0};	/* output information: summary */
 	struct __siov iov[NIOV];/* ... and individual io vectors */
 	char buf[BUF];		/* space for %c, %[diouxX], %[eEfgG] */
 	char ox[2];		/* space for 0x hex-prefix */
diff --git a/newlib/libc/stdio/fputs.c b/newlib/libc/stdio/fputs.c
index 75f65d9..0fda237 100644
--- a/newlib/libc/stdio/fputs.c
+++ b/newlib/libc/stdio/fputs.c
@@ -117,7 +117,7 @@ _DEFUN(_fputs_r, (ptr, s, fp),
 {
 #ifdef _FVWRITE_IN_STREAMIO
   int result;
-  struct __suio uio;
+  struct __suio uio = {0, 0, 0};
   struct __siov iov;
 
   iov.iov_base = s;
diff --git a/newlib/libc/stdio/fputws.c b/newlib/libc/stdio/fputws.c
index bb2fa6d..e5a333c 100644
--- a/newlib/libc/stdio/fputws.c
+++ b/newlib/libc/stdio/fputws.c
@@ -126,7 +126,7 @@ _DEFUN(_fputws_r, (ptr, ws, fp),
   size_t nbytes;
   char buf[BUFSIZ];
 #ifdef _FVWRITE_IN_STREAMIO
-  struct __suio uio;
+  struct __suio uio = {0, 0, 0};
   struct __siov iov;
 
   _newlib_flockfile_start (fp);
diff --git a/newlib/libc/stdio/fwrite.c b/newlib/libc/stdio/fwrite.c
index 6b3ff90..2e39cb0 100644
--- a/newlib/libc/stdio/fwrite.c
+++ b/newlib/libc/stdio/fwrite.c
@@ -149,7 +149,7 @@ _DEFUN(_fwrite_r, (ptr, buf, size, count, fp),
 {
   size_t n;
 #ifdef _FVWRITE_IN_STREAMIO
-  struct __suio uio;
+  struct __suio uio = {0, 0, 0};
   struct __siov iov;
 
   iov.iov_base = buf;
diff --git a/newlib/libc/stdio/puts.c b/newlib/libc/stdio/puts.c
index 7467371..d154406 100644
--- a/newlib/libc/stdio/puts.c
+++ b/newlib/libc/stdio/puts.c
@@ -81,7 +81,7 @@ _DEFUN(_puts_r, (ptr, s),
 #ifdef _FVWRITE_IN_STREAMIO
   int result;
   size_t c = strlen (s);
-  struct __suio uio;
+  struct __suio uio = {0, 0, 0};
   struct __siov iov[2];
   FILE *fp;
 
diff --git a/newlib/libc/stdio/vfprintf.c b/newlib/libc/stdio/vfprintf.c
index ed92bb2..d4bd1c8 100644
--- a/newlib/libc/stdio/vfprintf.c
+++ b/newlib/libc/stdio/vfprintf.c
@@ -718,7 +718,7 @@ _DEFUN(_VFPRINTF_R, (data, fp, fmt0, ap),
 	char *xdigs = NULL;	/* digits for [xX] conversion */
 #ifdef _FVWRITE_IN_STREAMIO
 #define NIOV 8
-	struct __suio uio;	/* output information: summary */
+	struct __suio uio = {0, 0, 0};	/* output information: summary */
 	struct __siov iov[NIOV];/* ... and individual io vectors */
 	register struct __siov *iovp;/* for PRINT macro */
 #endif
diff --git a/newlib/libc/stdio/vfwprintf.c b/newlib/libc/stdio/vfwprintf.c
index f0179a0..15504b5 100644
--- a/newlib/libc/stdio/vfwprintf.c
+++ b/newlib/libc/stdio/vfwprintf.c
@@ -438,7 +438,7 @@ _DEFUN(_VFWPRINTF_R, (data, fp, fmt0, ap),
 	wchar_t *xdigs = NULL;	/* digits for [xX] conversion */
 #ifdef _FVWRITE_IN_STREAMIO
 #define NIOV 8
-	struct __suio uio;	/* output information: summary */
+	struct __suio uio = {0, 0, 0};	/* output information: summary */
 	struct __siov iov[NIOV];/* ... and individual io vectors */
 	register struct __siov *iovp;/* for PRINT macro */
 #endif