diff --git a/lix/libcmd/built-path.cc b/lix/libcmd/built-path.cc
index bb4c03124..77f4f98a1 100644
--- a/lix/libcmd/built-path.cc
+++ b/lix/libcmd/built-path.cc
@@ -112,21 +112,7 @@ try {
                     staticOutputHashes(store, TRY_AWAIT(store.readDerivation(p.drvPath.path)))
                 );
                 for (auto& [outputName, outputPath] : p.outputs) {
-                    if (experimentalFeatureSettings.isEnabled(
-                                Xp::CaDerivations)) {
-                        auto drvOutput = get(drvHashes, outputName);
-                        if (!drvOutput)
-                            throw Error(
-                                "the derivation '%s' has unrealised output '%s' (derived-path.cc/toRealisedPaths)",
-                                store.printStorePath(p.drvPath.path), outputName);
-                        auto thisRealisation = TRY_AWAIT(store.queryRealisation(
-                            DrvOutput{*drvOutput, outputName}));
-                        assert(thisRealisation);  // We’ve built it, so we must
-                                                  // have the realisation
-                        res.insert(*thisRealisation);
-                    } else {
-                        res.insert(outputPath);
-                    }
+                    res.insert(outputPath);
                 }
                 co_return result::success();
             } catch (...) {
diff --git a/lix/libstore/misc.cc b/lix/libstore/misc.cc
index f29583834..39a9066ad 100644
--- a/lix/libstore/misc.cc
+++ b/lix/libstore/misc.cc
@@ -259,33 +259,7 @@ struct QueryMissingContext
         ParsedDerivation parsedDrv(StorePath(drvPath), *drv);
 
         if (!knownOutputPaths && settings.useSubstitutes && parsedDrv.substitutesAllowed()) {
-            experimentalFeatureSettings.require(Xp::CaDerivations);
-
-            // If there are unknown output paths, attempt to find if the
-            // paths are known to substituters through a realisation.
-            auto outputHashes = aio.blockOn(staticOutputHashes(store, *drv));
-            knownOutputPaths = true;
-
-            for (auto [outputName, hash] : outputHashes) {
-                if (!bfd.outputs.contains(outputName))
-                    continue;
-
-                bool found = false;
-                for (auto &sub : aio.blockOn(getDefaultSubstituters())) {
-                    auto realisation = aio.blockOn(sub->queryRealisation({hash, outputName}));
-                    if (!realisation)
-                        continue;
-                    found = true;
-                    if (!aio.blockOn(store.isValidPath(realisation->outPath)))
-                        invalid.insert(realisation->outPath);
-                    break;
-                }
-                if (!found) {
-                    // Some paths did not have a realisation, this must be built.
-                    knownOutputPaths = false;
-                    break;
-                }
-            }
+            throw UnimplementedError("ca derivations are not supported");
         }
 
         if (knownOutputPaths && settings.useSubstitutes && parsedDrv.substitutesAllowed()) {
diff --git a/lix/libstore/remote-store.cc b/lix/libstore/remote-store.cc
index 01b1bad5a..4daf270ba 100644
--- a/lix/libstore/remote-store.cc
+++ b/lix/libstore/remote-store.cc
@@ -743,20 +743,12 @@ try {
                                     "the derivation '%s' doesn't have an output named '%s'",
                                     printStorePath(drvPath), output);
                             auto outputId = DrvOutput{ *outputHash, output };
-                            if (experimentalFeatureSettings.isEnabled(Xp::CaDerivations)) {
-                                auto realisation =
-                                    TRY_AWAIT(queryRealisation(outputId));
-                                if (!realisation)
-                                    throw MissingRealisation(outputId);
-                                res.builtOutputs.emplace(output, *realisation);
-                            } else {
-                                res.builtOutputs.emplace(
-                                    output,
-                                    Realisation {
-                                        .id = outputId,
-                                        .outPath = outputPath,
-                                    });
-                            }
+                            res.builtOutputs.emplace(
+                                output,
+                                Realisation {
+                                    .id = outputId,
+                                    .outPath = outputPath,
+                                });
                         }
 
                         results.push_back(res);
diff --git a/lix/libstore/store-api.cc b/lix/libstore/store-api.cc
index 3d63e7b57..e882ca366 100644
--- a/lix/libstore/store-api.cc
+++ b/lix/libstore/store-api.cc
@@ -526,26 +526,7 @@ Store::queryPartialDerivationOutputMap(const StorePath & path, Store * evalStore
 try {
     auto & evalStore = evalStore_ ? *evalStore_ : *this;
 
-    auto outputs = TRY_AWAIT(evalStore.queryStaticPartialDerivationOutputMap(path));
-
-    if (!experimentalFeatureSettings.isEnabled(Xp::CaDerivations))
-        co_return outputs;
-
-    auto drv = TRY_AWAIT(evalStore.readInvalidDerivation(path));
-    auto drvHashes = TRY_AWAIT(staticOutputHashes(*this, drv));
-    for (auto & [outputName, hash] : drvHashes) {
-        auto realisation = TRY_AWAIT(queryRealisation(DrvOutput{hash, outputName}));
-        if (realisation) {
-            outputs.insert_or_assign(outputName, realisation->outPath);
-        } else {
-            // queryStaticPartialDerivationOutputMap is not guaranteed
-            // to return std::nullopt for outputs which are not
-            // statically known.
-            outputs.insert({outputName, std::nullopt});
-        }
-    }
-
-    co_return outputs;
+    co_return TRY_AWAIT(evalStore.queryStaticPartialDerivationOutputMap(path));
 } catch (...) {
     co_return result::current_exception();
 }