diff --git a/.github/workflows/ci2.yml b/.github/workflows/ci2.yml
index eca3e8ad525..b3be2ec39fc 100644
--- a/.github/workflows/ci2.yml
+++ b/.github/workflows/ci2.yml
@@ -90,6 +90,7 @@ jobs:
           #LIBS="$(nc-config --libs)" ./configure --enable-static --disable-shared --prefix=/mingw64
           #LIBS="$(nc-config --libs)" ./configure --enable-static --disable-shared
           LDFLAGS="-Wl,-no-undefined" LIBS="$(nc-config --libs)" ./configure --enable-shared
+          sed -i.bak -e "s/\(allow_undefined=\)yes/\1no/" libtool
           make install
           #ldconfig
           ls fortran/.libs