diff --git a/devel_tools/docker/frama-c.dev/Dockerfile b/devel_tools/docker/frama-c.dev/Dockerfile
index 564d718075519adaccb3582bcfc1273944af4e5e..22961c32a9bf219def31289fd5ff0bbeadef7d47 100644
--- a/devel_tools/docker/frama-c.dev/Dockerfile
+++ b/devel_tools/docker/frama-c.dev/Dockerfile
@@ -33,7 +33,7 @@ RUN apt-get update && opam update -y && opam depext --install -y --verbose \
     zmq.5.1.3 \
     && rm -rf /var/lib/apt/lists/*
 
-RUN why3 config --full-config
+RUN why3 config --detect
 
 # with_source: keep Frama-C sources
 ARG with_source=no
diff --git a/nix/default.nix b/nix/default.nix
index 230879d9bfa1c57e63e76208a5b8be54a176b1ee..39ca3878ecc176c7a8b6c8d0c9f208c737e5d74e 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -159,7 +159,7 @@ rec {
 
   wp-qualif = mk_deriv {
         name = "frama-c-wp-qualif";
-        buildInputs = mk_buildInputs { opamPackages = []; };
+        buildInputs = mk_buildInputs { };
         build_dir = main.build_dir;
         src = main.build_dir + "/dir.tar";
         sourceRoot = ".";
@@ -187,9 +187,7 @@ rec {
 
   aorai-prove = mk_deriv {
         name = "frama-c-aorai-prove";
-        buildInputs = mk_buildInputs { opamPackages = [
-                    { name = "alt-ergo"; constraint = "=2.0.0"; }
-               ]; };
+        buildInputs = mk_buildInputs { };
         build_dir = main.build_dir;
         src = main.build_dir + "/dir.tar";
         sourceRoot = ".";
@@ -205,7 +203,7 @@ rec {
           make create_share_link
           mkdir home
           HOME=$(pwd)/home
-          why3 config --full-config
+          why3 config --detect
           make src/plugins/aorai/tests/ptests_config
           make PTESTS_OPTS="-config prove -error-code" Aorai_TESTS
         '';