diff --git a/src/libfetchers/fetch-to-store.cc b/src/libfetchers/fetch-to-store.cc
index 7c5c5be1036f..8dfb74a9c5af 100644
--- a/src/libfetchers/fetch-to-store.cc
+++ b/src/libfetchers/fetch-to-store.cc
@@ -46,6 +46,12 @@ std::pair<StorePath, Hash> fetchToStore2(
             auto hash = Hash::parseSRI(fetchers::getStrAttr(*res, "hash"));
             auto storePath =
                 store.makeFixedOutputPathFromCA(name, ContentAddressWithReferences::fromParts(method, hash, {}));
+
+            /* Add a temproot before the call to isValidPath to prevent accidental GC in case the
+               input is cached. Note that this must be done before to avoid races. */
+            if (mode != FetchMode::DryRun)
+                store.addTempRoot(storePath);
+
             if (mode == FetchMode::DryRun || store.maybeQueryPathInfo(storePath)) {
                 debug(
                     "source path '%s' cache hit in '%s' (hash '%s')",
diff --git a/src/libstore/async-path-writer.cc b/src/libstore/async-path-writer.cc
index 925c52ea371a..dce38b526478 100644
--- a/src/libstore/async-path-writer.cc
+++ b/src/libstore/async-path-writer.cc
@@ -160,6 +160,7 @@ struct AsyncPathWriterImpl : AsyncPathWriter
 
         for (auto & item : items) {
             StringSource source(item.contents);
+            store->addTempRoot(item.storePath);
             auto storePath = store->addToStoreFromDump(
                 source,
                 item.storePath.name(),
diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 8dc185e45543..5994e7cb43eb 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -146,6 +146,12 @@ Store::writeDerivation(const Derivation & drv, RepairFlag repair, std::shared_pt
 {
     auto [suffix, contents, references, path] = infoForDerivation(*this, drv);
 
+    /* In case the derivation is already valid, we bail out early since that's
+       faster. But we need to make sure that the derivation has a corresponding
+       temproot. It is added by the remote in addToStoreFromDump, but we'd like
+       to avoid sending a lot of drv contents to the daemon. */
+    addTempRoot(path);
+
     if (isValidPath(path) && !repair)
         return path;