diff --git a/lix/libstore/derivations.cc b/lix/libstore/derivations.cc
index 9f02eba30..e437a2b2f 100644
--- a/lix/libstore/derivations.cc
+++ b/lix/libstore/derivations.cc
@@ -256,13 +256,7 @@ static DerivationOutput parseDerivationOutput(
                 },
             };
         } else {
-            xpSettings.require(Xp::CaDerivations);
-            if (pathS != "")
-                throw FormatError("content-addressed derivation output should not specify output path");
-            return DerivationOutput::CAFloating {
-                .method = std::move(method),
-                .hashType = std::move(hashType),
-            };
+            throw UnimplementedError("ca derivations are not supported");
         }
     } else {
         if (pathS == "") {
@@ -923,19 +917,10 @@ static bool tryResolveInput(
         return actualPathOpt;
     };
 
-    auto getPlaceholder = [&](const std::string & outputName) {
-        return DownstreamPlaceholder::unknownCaOutput(inputDrv, outputName);
-    };
-
     for (auto & outputName : inputNode) {
         auto actualPathOpt = getOutput(outputName);
         if (!actualPathOpt) return false;
         auto actualPath = *actualPathOpt;
-        if (experimentalFeatureSettings.isEnabled(Xp::CaDerivations)) {
-            inputRewrites.emplace(
-                getPlaceholder(outputName).render(),
-                store.printStorePath(actualPath));
-        }
         inputSrcs.insert(std::move(actualPath));
     }
 
@@ -1104,12 +1089,7 @@ DerivationOutput DerivationOutput::fromJSON(
     }
 
     else if (keys == (std::set<std::string_view> { "hashAlgo" })) {
-        xpSettings.require(Xp::CaDerivations);
-        auto [method, hashType] = methodAlgo();
-        return DerivationOutput::CAFloating {
-            .method = std::move(method),
-            .hashType = std::move(hashType),
-        };
+        throw UnimplementedError("ca derivations are not supported");
     }
 
     else if (keys == (std::set<std::string_view> { })) {
diff --git a/tests/unit/libstore/data/libstore/derivation/output-caFloating.json b/tests/unit/libstore/data/libstore/derivation/output-caFloating.json
deleted file mode 100644
index 9115de851..000000000
--- a/tests/unit/libstore/data/libstore/derivation/output-caFloating.json
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-  "hashAlgo": "r:sha256"
-}
diff --git a/tests/unit/libstore/derivation.cc b/tests/unit/libstore/derivation.cc
index 69fe7c484..21788ecf9 100644
--- a/tests/unit/libstore/derivation.cc
+++ b/tests/unit/libstore/derivation.cc
@@ -26,14 +26,6 @@ public:
     }
 };
 
-class CaDerivationTest : public DerivationTest
-{
-    void SetUp() override
-    {
-        mockXpSettings.experimentalFeatures.override(ExperimentalFeatures{} | Xp::CaDerivations);
-    }
-};
-
 TEST_F(DerivationTest, BadATerm_version) {
     ASSERT_THROW(
         parseDerivation(
@@ -110,13 +102,6 @@ TEST_JSON(DerivationTest, caFixedNAR,
     }),
     "drv-name", "output-name")
 
-TEST_JSON(CaDerivationTest, caFloating,
-    (DerivationOutput::CAFloating {
-        .method = FileIngestionMethod::Recursive,
-        .hashType = HashType::SHA256,
-    }),
-    "drv-name", "output-name")
-
 TEST_JSON(DerivationTest, deferred,
     DerivationOutput::Deferred { },
     "drv-name", "output-name")