diff --git a/Makefile.in b/Makefile.in
index f588bf5e3..dff824b19 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -77,7 +77,7 @@ PS2PDF = @PS2PDF@
 GIT = @GIT@
 
 CPPFLAGS = @DEFS@ -I. -I$(srcdir) @CPPFLAGS@
-CXXFLAGS = -Wall @CXXFLAGS@
+CXXFLAGS = @WARNING_CXXFLAGS@ @CXXFLAGS@
 PICFLAGS = @PICFLAG@
 LDFLAGS = @rdynamic@ @LDFLAGS@
 
diff --git a/configure.in b/configure.in
index c0c066eee..8e55142b7 100644
--- a/configure.in
+++ b/configure.in
@@ -62,6 +62,8 @@ AC_CHECK_DECL(__SUNPRO_C,AC_SUBST(WARNING_CFLAGS,),AC_SUBST(WARNING_CFLAGS,-Wall
 
 AC_LANG(C++)
 
+AC_CHECK_DECL(__SUNPRO_CC,AC_SUBST(WARNING_CXXFLAGS,),AC_SUBST(WARNING_CXXFLAGS,-Wall))
+
 AC_CHECK_HEADERS(getopt.h malloc.h inttypes.h libiberty.h iosfwd sys/wait.h)
 
 AC_CHECK_SIZEOF(unsigned long long)