2 files changed, 12 insertions, 4 deletions
diff --git a/numeric.c b/numeric.c
index b4ea8b2578..1716efb400 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1347,13 +1347,23 @@ Perl_isinfnan(NV nv)
     return FALSE;
 }
 
-#if ! defined(HAS_MODFL) && defined(HAS_AINTL) && defined(HAS_COPYSIGNL)
+#ifndef HAS_MODFL
+/* C99 has truncl, pre-C99 Solaris had aintl */
+#  if defined(HAS_TRUNCL) && defined(HAS_COPYSIGNL)
+long double
+Perl_my_modfl(long double x, long double *ip)
+{
+	*ip = truncl(x);
+	return (x == *ip ? copysignl(0.0L, x) : x - *ip);
+}
+#  elif defined(HAS_AINTL) && defined(HAS_COPYSIGNL)
 long double
 Perl_my_modfl(long double x, long double *ip)
 {
 	*ip = aintl(x);
 	return (x == *ip ? copysignl(0.0L, x) : x - *ip);
 }
+#  endif
 #endif
 
 #if ! defined(HAS_FREXPL) && defined(HAS_ILOGBL) && defined(HAS_SCALBNL)
diff --git a/perl.h b/perl.h
index f3ae3eb6aa..f94c6175cf 100644
--- a/perl.h
+++ b/perl.h
@@ -1912,11 +1912,9 @@ typedef NVTYPE NV;
 #       ifndef HAS_MODFL_PROTO
 EXTERN_C long double modfl(long double, long double *);
 #	endif
-#   else
-#       if defined(HAS_AINTL) && defined(HAS_COPYSIGNL)
+#   elif (defined(HAS_TRUNCL) || defined(HAS_AINTL)) && defined(HAS_COPYSIGNL)
         extern long double Perl_my_modfl(long double x, long double *ip);
 #           define Perl_modf(x,y) Perl_my_modfl(x,y)
-#       endif
 #   endif
 #   ifdef HAS_FREXPL
 #       define Perl_frexp(x,y) frexpl(x,y)