diff --git a/zcutil/build.sh b/zcutil/build.sh
index 17f023991..6b142990c 100755
--- a/zcutil/build.sh
+++ b/zcutil/build.sh
@@ -41,6 +41,11 @@ if [[ -z "${CXX-}" ]]; then
     CXX=g++
 fi
 
+# Allow users to set arbitary compile flags. Most users will not need this.
+if [[ -z "${CONFIGURE_FLAGS-}" ]]; then
+    CONFIGURE_FLAGS=""
+fi
+
 if [ "x$*" = 'x--help' ]
 then
     cat <<EOF
@@ -132,5 +137,5 @@ ld -v
 
 HOST="$HOST" BUILD="$BUILD" NO_RUST="$RUST_ARG" NO_PROTON="$PROTON_ARG" "$MAKE" "$@" -C ./depends/ V=1
 ./autogen.sh
-CC="$CC" CXX="$CXX" ./configure --prefix="${PREFIX}" --host="$HOST" --build="$BUILD" "$RUST_ARG" "$HARDENING_ARG" "$LCOV_ARG" "$TEST_ARG" "$MINING_ARG" "$PROTON_ARG" "$LIBS_ARG" --enable-werror CXXFLAGS='-g'
+CC="$CC" CXX="$CXX" ./configure --prefix="${PREFIX}" --host="$HOST" --build="$BUILD" "$RUST_ARG" "$HARDENING_ARG" "$LCOV_ARG" "$TEST_ARG" "$MINING_ARG" "$PROTON_ARG" "$LIBS_ARG" $CONFIGURE_FLAGS --enable-werror CXXFLAGS='-g'
 "$MAKE" "$@" V=1