diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index cdd3f118216..e725012e0f5 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,9 @@
+2005-08-03  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
+
+	* libgfortran.h: When isfinite is not provided by the system,
+	define it as a macro, so that it can accept any floating point
+	type.
+
 2005-08-01  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
 
 	PR libfortran/23178
diff --git a/libgfortran/libgfortran.h b/libgfortran/libgfortran.h
index ccba2a764be..6db6ef927cf 100644
--- a/libgfortran/libgfortran.h
+++ b/libgfortran/libgfortran.h
@@ -179,17 +179,11 @@ typedef off_t gfc_offset;
    alternatives, or bail out.  */
 #if (!defined(isfinite) || defined(__CYGWIN__))
 #undef isfinite
-static inline int
-isfinite (double x)
-{
 #if defined(fpclassify)
-  return (fpclassify(x) != FP_NAN && fpclassify(x) != FP_INFINITE);
-#elif defined(HAVE_FINITE)
-  return finite (x);
+#define isfinite(x) (fpclassify(x) != FP_NAN && fpclassify(x) != FP_INFINITE)
 #else
-#error "libgfortran needs isfinite, fpclassify, or finite"
+#define isfinite(x) ((x) - (x) == 0)
 #endif
-}
 #endif /* !defined(isfinite)  */
 
 /* TODO: find the C99 version of these an move into above ifdef.  */