diff --git a/src/libexpr/include/nix/expr/attr-set.hh b/src/libexpr/include/nix/expr/attr-set.hh
index e01b6729c..85bba1099 100644
--- a/src/libexpr/include/nix/expr/attr-set.hh
+++ b/src/libexpr/include/nix/expr/attr-set.hh
@@ -22,7 +22,7 @@ struct Attr
        way we keep Attr size at two words with no wasted space. */
     Symbol name;
     PosIdx pos;
-    Value * value;
+    Value * value = nullptr;
     Attr(Symbol name, Value * value, PosIdx pos = noPos)
         : name(name)
         , pos(pos)
diff --git a/src/libstore/derivation-options.cc b/src/libstore/derivation-options.cc
index f1515c308..6656a4798 100644
--- a/src/libstore/derivation-options.cc
+++ b/src/libstore/derivation-options.cc
@@ -144,7 +144,7 @@ DerivationOptions::fromStructuredAttrs(const StringMap & env, const StructuredAt
                         if (auto maxClosureSize = get(output, "maxClosureSize"))
                             checks.maxClosureSize = maxClosureSize->get<uint64_t>();
 
-                        auto get_ = [&](const std::string & name) -> std::optional<StringSet> {
+                        auto get_ = [&output = output](const std::string & name) -> std::optional<StringSet> {
                             if (auto i = get(output, name)) {
                                 StringSet res;
                                 for (auto j = i->begin(); j != i->end(); ++j) {
diff --git a/src/libstore/include/nix/store/s3.hh b/src/libstore/include/nix/store/s3.hh
index f0ed2fefd..57e03a065 100644
--- a/src/libstore/include/nix/store/s3.hh
+++ b/src/libstore/include/nix/store/s3.hh
@@ -1,6 +1,6 @@
 #pragma once
 ///@file
-#include "store-config-private.hh"
+#include "nix/store/config.hh"
 #if NIX_WITH_S3_SUPPORT
 
 #  include "nix/util/ref.hh"
diff --git a/src/libstore/linux/fchmodat2-compat.hh b/src/libstore/linux/fchmodat2-compat.hh
index 42b3f3a35..907695c31 100644
--- a/src/libstore/linux/fchmodat2-compat.hh
+++ b/src/libstore/linux/fchmodat2-compat.hh
@@ -1,4 +1,5 @@
 #include "store-config-private.hh"
+#include <cstdint>
 
 /*
  * Determine the syscall number for `fchmodat2`.