diff --git a/Makefile.am b/Makefile.am
index 59b25c03..aea720c2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -7,7 +7,7 @@ hyperrogue_SOURCES = hyper.cpp savepng.c
 
 # Some definitions used in graph.cpp
 hyperrogue_CPPFLAGS = -DFONTDESTDIR=\"$(pkgdatadir)/DejaVuSans-Bold.ttf\" -DMUSICDESTDIR=\"$(pkgdatadir)/hyperrogue-music.txt\" -DSOUNDDESTDIR=\"$(pkgdatadir)/sounds/\"
-hyperrogue_CPPFLAGS += -std=c++11
+hyperrogue_CXXFLAGS = -std=c++11
 
 # Musicdir
 musicdir=$(datadir)/hyperrogue/music