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--- a/src/mk/Linux
+++ b/src/mk/Linux
@@ -3,6 +3,7 @@
 
 CXXFLAGS = $(COMMONCXXFLAGS) $(LOCALCXXFLAGS) \
 	 -D_GNU_SOURCE \
+         -DPUTENV_ARG_NOT_CONST \
 	 -DHAVE_VASPRINTF=1 \
 	 -DHAVE_MKDTEMP=1