diff --git a/apis/r/src/Makevars.in b/apis/r/src/Makevars.in
index 1849b4d3f1..fe118a4c9d 100644
--- a/apis/r/src/Makevars.in
+++ b/apis/r/src/Makevars.in
@@ -1,7 +1,7 @@
-#CXX_STD = CXX20
+CXX_STD = CXX20
 
 ## We need the TileDB Headers, and for macOS aka Darwin need to set minimum version 13.3 for macOS
-PKG_CPPFLAGS = -std=c++20 -I. -I../inst/include/ @tiledb_include@ @cxx20_macos@ -DSPDLOG_USE_STD_FORMAT
+PKG_CPPFLAGS = -I. -I../inst/include/ @tiledb_include@ @cxx20_macos@ -DSPDLOG_USE_STD_FORMAT
 
 ## We also need the TileDB library
 PKG_LIBS = @cxx20_macos@ @tiledb_libs@ @tiledb_rpath@