diff --git a/.github/workflows/builds.yml b/.github/workflows/builds.yml
index fae577846663..06accb9147e9 100644
--- a/.github/workflows/builds.yml
+++ b/.github/workflows/builds.yml
@@ -1433,7 +1433,7 @@ jobs:
       - run: tar xvf prep/libhtp.tar.gz
       - run: tar xvf prep/suricata-update.tar.gz
       - run: ./autogen.sh
-      - run: CFLAGS="${DEFAULT_CFLAGS}" CPPFLAGS="-I/usr/local/opt/libiconv/include" ./configure --enable-unittests
+      - run: CFLAGS="${DEFAULT_CFLAGS}" CPPFLAGS="-I/usr/local/opt/libiconv/include" CXXFLAGS="-I/usr/local/opt/libiconv/include" ./configure --enable-unittests
       - run: make -j2
       # somehow it gets included by some C++ stdlib header (case unsensitive)
       - run: rm libhtp/VERSION && make check