diff --git a/polymake.spec b/polymake.spec
index 3b0fa17..20373c7 100644
--- a/polymake.spec
+++ b/polymake.spec
@@ -176,7 +176,7 @@ sed -e '/^\$LDsharedFlags=/a$LDsharedFlags =~ s/ -specs=\\S+//g;' \
 
 %build
 export CFLAGS="%{optflags} -I%{_includedir}/eigen3 -Wno-unused-local-typedefs"
-export CXXFLAGS="$CFLAGS"
+export CXXFLAGS="$CFLAGS -std=gnu++98"
 export LDFLAGS="$RPM_LD_FLAGS -Wl,--as-needed -ldl"
 export Arch=%{_arch}
 # NOT an autoconf-generated configure script; do not use %%configure.