diff --git a/src/Makefile.am b/src/Makefile.am
index 7d61bd19d..6e3569ab3 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -418,6 +418,8 @@ libzcash_a_SOURCES = \
 
 libzcash_a_CPPFLAGS = -DMULTICORE -fopenmp -fPIC -DBINARY_OUTPUT -DCURVE_ALT_BN128 -DBOOST_SPIRIT_THREADSAFE -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS $(HARDENED_CPPFLAGS) $(HARDENED_CXXFLAGS) $(HARDENED_LDFLAGS) -pipe -O1 -g -Wstack-protector -fstack-protector-all -fPIE -fvisibility=hidden -DSTATIC $(BITCOIN_INCLUDES)
 
+libzcash_a_CPPFLAGS += -DMONTGOMERY_OUTPUT
+
 # bitcoinconsensus library #
 if BUILD_BITCOIN_LIBS
 include_HEADERS = script/bitcoinconsensus.h