diff --git a/doc/manual/rl-next/json-format-changes.md b/doc/manual/rl-next/json-format-changes.md
index c5518ee1b..ef442c27e 100644
--- a/doc/manual/rl-next/json-format-changes.md
+++ b/doc/manual/rl-next/json-format-changes.md
@@ -22,7 +22,7 @@ The store path info JSON format has been updated from version 1 to version 2:
   - New: `"ca": {"method": "nar", "hash": {"algorithm": "sha256", "format": "base64", "hash": "EMIJ+giQ..."}}`
   - Still `null` values for input-addressed store objects
 
-Version 1 format is still accepted when reading for backward compatibility.
+Nix currently only produces, and doesn't consume this format.
 
 **Affected command**: `nix path-info --json`
 
diff --git a/src/libstore/derivation-options.cc b/src/libstore/derivation-options.cc
index 75313841c..265f28e80 100644
--- a/src/libstore/derivation-options.cc
+++ b/src/libstore/derivation-options.cc
@@ -423,15 +423,6 @@ void adl_serializer<DerivationOptions>::to_json(json & json, const DerivationOpt
     json["allowSubstitutes"] = o.allowSubstitutes;
 }
 
-template<typename T>
-static inline std::optional<T> ptrToOwned(const json * ptr)
-{
-    if (ptr)
-        return std::optional{*ptr};
-    else
-        return std::nullopt;
-}
-
 DerivationOptions::OutputChecks adl_serializer<DerivationOptions::OutputChecks>::from_json(const json & json_)
 {
     auto & json = getObject(json_);
diff --git a/src/libstore/path-info.cc b/src/libstore/path-info.cc
index c535d08f4..7d8bf4911 100644
--- a/src/libstore/path-info.cc
+++ b/src/libstore/path-info.cc
@@ -192,13 +192,10 @@ UnkeyedValidPathInfo UnkeyedValidPathInfo::fromJSON(const StoreDirConfig & store
 
     auto & json = getObject(_json);
 
-    // Check version (optional for backward compatibility)
-    nlohmann::json::number_unsigned_t version = 1;
-    if (json.contains("version")) {
-        version = getUnsigned(valueAt(json, "version"));
-        if (version != 1 && version != 2) {
-            throw Error("Unsupported path info JSON format version %d, expected 1 through 2", version);
-        }
+    {
+        auto version = getUnsigned(valueAt(json, "version"));
+        if (version != 2)
+            throw Error("Unsupported path info JSON format version %d, only version 2 is currently supported", version);
     }
 
     res.narHash = Hash::parseAny(getString(valueAt(json, "narHash")), std::nullopt);
@@ -213,19 +210,12 @@ UnkeyedValidPathInfo UnkeyedValidPathInfo::fromJSON(const StoreDirConfig & store
         throw;
     }
 
-    // New format as this as nullable but mandatory field; handling
-    // missing is for back-compat.
-    if (auto * rawCa0 = optionalValueAt(json, "ca"))
-        if (auto * rawCa = getNullable(*rawCa0))
-            switch (version) {
-            case 1:
-                // old string format also used in SQLite DB and .narinfo
-                res.ca = ContentAddress::parse(getString(*rawCa));
-                break;
-            case 2 ... std::numeric_limits<decltype(version)>::max():
-                res.ca = *rawCa;
-                break;
-            }
+    try {
+        res.ca = ptrToOwned<ContentAddress>(getNullable(valueAt(json, "ca")));
+    } catch (Error & e) {
+        e.addTrace({}, "while reading key 'ca'");
+        throw;
+    }
 
     if (auto * rawDeriver0 = optionalValueAt(json, "deriver"))
         if (auto * rawDeriver = getNullable(*rawDeriver0))
diff --git a/src/libutil/include/nix/util/json-utils.hh b/src/libutil/include/nix/util/json-utils.hh
index 7a3fe4f36..ec513ca25 100644
--- a/src/libutil/include/nix/util/json-utils.hh
+++ b/src/libutil/include/nix/util/json-utils.hh
@@ -114,4 +114,13 @@ struct adl_serializer<std::optional<T>>
     }
 };
 
+template<typename T>
+static inline std::optional<T> ptrToOwned(const json * ptr)
+{
+    if (ptr)
+        return std::optional{*ptr};
+    else
+        return std::nullopt;
+}
+
 } // namespace nlohmann