diff --git a/src/Makevars b/src/Makevars
index 323fe95..9f2426e 100644
--- a/src/Makevars
+++ b/src/Makevars
@@ -1,4 +1,3 @@
-CXX_STD = CXX11
 PKG_LIBS = -pthread
 PKG_CPPFLAGS = -pthread -DSTRICT_R_HEADERS -I./word2vec/include -I./word2vec/lib
 
diff --git a/src/Makevars.win b/src/Makevars.win
index 512ca4d..0affdf1 100644
--- a/src/Makevars.win
+++ b/src/Makevars.win
@@ -1,4 +1,3 @@
-CXX_STD = CXX11
 PKG_LIBS = -pthread
 PKG_CPPFLAGS = -pthread -DSTRICT_R_HEADERS -I./word2vec/include -I./word2vec/lib