diff --git a/.env.example b/.env.example
index 9515602..662bc36 100644
--- a/.env.example
+++ b/.env.example
@@ -44,7 +44,7 @@ GNUNET_REF=v0.26.1
 EXCHANGE_REF=master
 MERCHANT_REF=master
 LIBEUFIN_REF=master
-GNUNET_TARBALL_URL=https://git-www.taler.net/gnunet.git/snapshot/gnunet-512c42a713e52a2033928a302e445376d3bcb3a7.tar.gz
+GNUNET_TARBALL_URL=
 EXCHANGE_TARBALL_URL=
 MERCHANT_TARBALL_URL=
 LIBEUFIN_TARBALL_URL=
diff --git a/Dockerfile b/Dockerfile
index a51781a..2842ee6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -92,7 +92,17 @@ RUN set -e; \
       if [ -f "${EXCHANGE_DIR}/configure" ]; then \
         echo "Using existing configure for Exchange tarball"; \
       else \
-        cd "${EXCHANGE_DIR}" && autoreconf -fi; \
+        set +e; \
+        (cd "${EXCHANGE_DIR}" && autoreconf -fi); \
+        rc=$?; \
+        set -e; \
+        if [ $rc -ne 0 ]; then \
+          echo "Autoreconf failed for Exchange tarball; falling back to git clone ${EXCHANGE_REF}"; \
+          rm -rf "${EXCHANGE_DIR}"; \
+          git clone --depth 1 --branch "${EXCHANGE_REF}" https://git.taler.net/exchange.git /src/exchange; \
+          EXCHANGE_DIR="/src/exchange"; \
+          cd "${EXCHANGE_DIR}" && env GNUNET_PREFIX=/usr ./bootstrap; \
+        fi; \
       fi; \
     else \
       if [ ! -f "${EXCHANGE_DIR}/configure" ]; then \
@@ -127,7 +137,17 @@ RUN set -e; \
       if [ -f "${MERCHANT_DIR}/configure" ]; then \
         echo "Using existing configure for Merchant tarball"; \
       else \
-        cd "${MERCHANT_DIR}" && autoreconf -fi; \
+        set +e; \
+        (cd "${MERCHANT_DIR}" && autoreconf -fi); \
+        rc=$?; \
+        set -e; \
+        if [ $rc -ne 0 ]; then \
+          echo "Autoreconf failed for Merchant tarball; falling back to git clone ${MERCHANT_REF}"; \
+          rm -rf "${MERCHANT_DIR}"; \
+          git clone --depth 1 --branch "${MERCHANT_REF}" https://git.taler.net/merchant.git /src/merchant; \
+          MERCHANT_DIR="/src/merchant"; \
+          cd "${MERCHANT_DIR}" && env GNUNET_PREFIX=/usr ./bootstrap; \
+        fi; \
       fi; \
     else \
       if [ ! -f "${MERCHANT_DIR}/configure" ]; then \