diff --git a/share/Makefile.config.in b/share/Makefile.config.in
index ed2c149f201bb7ef37bc5f5d10e4402dd173519a..505153e2f1f6a9204002f5b82a59d777febce816 100644
--- a/share/Makefile.config.in
+++ b/share/Makefile.config.in
@@ -189,6 +189,7 @@ ENABLE_METRICS	                  ?=@ENABLE_METRICS@
 ENABLE_OCCURRENCE                 ?=@ENABLE_OCCURRENCE@
 ENABLE_PDG	                  ?=@ENABLE_PDG@
 ENABLE_POSTDOMINATORS             ?=@ENABLE_POSTDOMINATORS@
+ENABLE_REDUC                      ?=@ENABLE_REDUC@
 ENABLE_RTEGEN                     ?=@ENABLE_RTEGEN@
 ENABLE_SCOPE	                  ?=@ENABLE_SCOPE@
 ENABLE_SLICING	                  ?=@ENABLE_SLICING@