diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index c3248c2c3..0bea40bd9 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -691,13 +691,20 @@ static void canonicalisePathMetaData_(
         if ((eaSize = llistxattr(path.c_str(), eaBuf.data(), eaBuf.size())) < 0)
             throw SysError("querying extended attributes of '%s'", path);
 
-        if (S_ISREG(st.st_mode) || S_ISDIR(st.st_mode))
+        bool resetMode = false;
+        if ((S_ISREG(st.st_mode) || S_ISDIR(st.st_mode)) && !(st.st_mode & S_IWUSR)) {
+            resetMode = true;
             chmod(path.c_str(), st.st_mode | S_IWUSR);
+        }
         for (auto & eaName: tokenizeString<Strings>(std::string(eaBuf.data(), eaSize), std::string("\000", 1))) {
             if (settings.ignoredAcls.get().count(eaName)) continue;
             if (lremovexattr(path.c_str(), eaName.c_str()) == -1)
                 throw SysError("removing extended attribute '%s' from '%s'", eaName, path);
         }
+        if (resetMode) {
+            chmod(path.c_str(), st.st_mode);
+            resetMode = false;
+        }
      }
 #endif
 
diff --git a/tests/functional/flakes/flakes.sh b/tests/functional/flakes/flakes.sh
index 75cc329e5..85ffacf70 100644
--- a/tests/functional/flakes/flakes.sh
+++ b/tests/functional/flakes/flakes.sh
@@ -285,11 +285,11 @@ nix build -o $TEST_ROOT/result $flake3Dir#sth --commit-lock-file
 
 Flake lock file updates:
 
-"?" Added input 'nonFlake':
+• Added input 'nonFlake':
     'git+file://"*"/flakes/flakes/nonFlake?ref=refs/heads/master&rev="*"' "*"
-"?" Added input 'nonFlakeFile':
+• Added input 'nonFlakeFile':
     'path:"*"/flakes/flakes/nonFlake/README.md?lastModified="*"&narHash=sha256-cPh6hp48IOdRxVV3xGd0PDgSxgzj5N/2cK0rMPNaR4o%3D' "*"
-"?" Added input 'nonFlakeFile2':
+• Added input 'nonFlakeFile2':
     'path:"*"/flakes/flakes/nonFlake/README.md?lastModified="*"&narHash=sha256-cPh6hp48IOdRxVV3xGd0PDgSxgzj5N/2cK0rMPNaR4o%3D' "* ]]
 
 nix build -o $TEST_ROOT/result flake3#fnord
diff --git a/tests/unit/libstore-support/tests/libstore.hh b/tests/unit/libstore-support/tests/libstore.hh
index ef93457b5..75093d3cd 100644
--- a/tests/unit/libstore-support/tests/libstore.hh
+++ b/tests/unit/libstore-support/tests/libstore.hh
@@ -4,6 +4,7 @@
 #include <gtest/gtest.h>
 #include <gmock/gmock.h>
 
+#include "globals.hh"
 #include "store-api.hh"
 
 namespace nix {
@@ -11,6 +12,7 @@ namespace nix {
 class LibStoreTest : public ::testing::Test {
     public:
         static void SetUpTestSuite() {
+            settings.nixConfDir = "/dev/null"; // intentionally invalid path
             initLibStore();
         }