diff --git a/src/Makevars.in b/src/Makevars.in
index d494013e..0de473c1 100644
--- a/src/Makevars.in
+++ b/src/Makevars.in
@@ -3,8 +3,7 @@ BH=@BH@
 RCPP=@RCPP@
 EG=@EG@
 SH=@SH@
-CXX_STD = CXX14
-CXX14STD = @CXX14STD@
+CXX_STD = CXX17
 
 ################################################################################
 ## Package library flags.