diff --git a/Makefile.am b/Makefile.am
index 72b21f0a..a395ecdb 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -12,8 +12,8 @@ dist_EXTRA_tmux_SOURCES = compat/*.[ch]
 
 # Preprocessor flags.
 AM_CPPFLAGS += @XOPEN_DEFINES@ \
-	-DTMUX_VERSION="\"@VERSION@\"" \
-	-DTMUX_CONF="\"$(sysconfdir)/tmux.conf:~/.tmux.conf:~/.config/tmux/tmux.conf\""
+	-DTMUX_VERSION='"@VERSION@"' \
+	-DTMUX_CONF='"$(sysconfdir)/tmux.conf:~/.tmux.conf:$$XDG_CONFIG_HOME/tmux/tmux.conf:~/.config/tmux/tmux.conf"'
 
 # Additional object files.
 LDADD = $(LIBOBJS)