diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 6678bc4d2..95ada5031 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,10 @@
+2003-07-09  Alexandre Oliva  <aoliva@redhat.com>
+
+	* libc/include/math.h (nan, nanf): Update prototype to C99.
+	* libm/common/s_nan.c (nan): Likewise.
+	* libm/common/s_nanf.c (nanf, nan): Likewise.
+	* libc/sys/linux/cmath/math_private.h (nan, nanf): Likewise.
+
 2003-07-07  Jeff Johnston  <jjohnstn@redhat.com>
 
 	* libc/include/stdbool.h: Removed as this is defined by gcc.
diff --git a/newlib/libc/include/math.h b/newlib/libc/include/math.h
index 16098c66c..1be7511dc 100644
--- a/newlib/libc/include/math.h
+++ b/newlib/libc/include/math.h
@@ -119,7 +119,7 @@ extern int __fpclassifyd (double x);
 /* Non ANSI double precision functions.  */
 
 extern double infinity _PARAMS((void));
-extern double nan _PARAMS((void));
+extern double nan _PARAMS((const char *));
 extern int isnan _PARAMS((double));
 extern int isinf _PARAMS((double));
 extern int finite _PARAMS((double));
@@ -234,7 +234,7 @@ extern float fminf _PARAMS((float, float));
 extern float fmaf _PARAMS((float, float, float));
 
 extern float infinityf _PARAMS((void));
-extern float nanf _PARAMS((void));
+extern float nanf _PARAMS((const char *));
 extern int isnanf _PARAMS((float));
 extern int isinff _PARAMS((float));
 extern int finitef _PARAMS((float));
diff --git a/newlib/libc/sys/linux/cmath/math_private.h b/newlib/libc/sys/linux/cmath/math_private.h
index 6c4a472cf..148376c44 100644
--- a/newlib/libc/sys/linux/cmath/math_private.h
+++ b/newlib/libc/sys/linux/cmath/math_private.h
@@ -24,14 +24,14 @@
 
 #define INFINITY HUGE_VALF
 
-#define __nan(x) nan()
+#define __nan nan
 #define __isnan isnan
 #define __isinf isinf
 #define __copysignf copysignf
 #define __copysign copysign
 #define __isnanf isnanf
 #define __isinff isinff
-#define __nanf(x) nanf()
+#define __nanf nanf
 #define feraiseexcept(x) /* nothing */
 #define __sincos sincos
 #define __sincosf sincosf
diff --git a/newlib/libm/common/s_nan.c b/newlib/libm/common/s_nan.c
index f06242647..a7d4dadf8 100644
--- a/newlib/libm/common/s_nan.c
+++ b/newlib/libm/common/s_nan.c
@@ -14,8 +14,8 @@ INDEX
 
 ANSI_SYNOPSIS
 	#include <math.h>
-	double nan(void);
-	float nanf(void);
+	double nan(const char *);
+	float nanf(const char *);
 
 TRAD_SYNOPSIS
 	#include <math.h>
@@ -25,7 +25,8 @@ TRAD_SYNOPSIS
 
 DESCRIPTION
 	<<nan>> and <<nanf>> return an IEEE NaN (Not a Number) in
-	double and single precision arithmetic respectivly.
+	double and single precision arithmetic respectivly.  The
+	argument is currently disregarded.
 
 QUICKREF
 	nan - pure
@@ -36,7 +37,7 @@ QUICKREF
 
 #ifndef _DOUBLE_IS_32BITS
 
-	double nan()
+	double nan(const char *unused)
 {
 	double x;
 
diff --git a/newlib/libm/common/sf_nan.c b/newlib/libm/common/sf_nan.c
index c8d7027f8..831f3f79f 100644
--- a/newlib/libm/common/sf_nan.c
+++ b/newlib/libm/common/sf_nan.c
@@ -5,7 +5,7 @@
 
 #include "fdlibm.h"
 
-	float nanf()
+	float nanf(const char *unused)
 {
 	float x;
 
@@ -15,9 +15,9 @@
 
 #ifdef _DOUBLE_IS_32BITS
 
-	double nan()
+	double nan(const char *arg)
 {
-	return (double) nanf();
+	return (double) nanf(arg);
 }
 
 #endif /* defined(_DOUBLE_IS_32BITS) */