diff --git a/third_party/nix/src/libutil/args.hh b/third_party/nix/src/libutil/args.hh
index ba6582abe..636375333 100644
--- a/third_party/nix/src/libutil/args.hh
+++ b/third_party/nix/src/libutil/args.hh
@@ -8,7 +8,7 @@
 
 namespace nix {
 
-MakeError(UsageError, Error);
+MakeError(UsageError, Error)
 
 enum HashType : char;
 
@@ -118,14 +118,14 @@ class Args {
       flag->arity = 1;
       flag->handler = [=](std::vector<std::string> ss) { *dest = ss[0]; };
       return *this;
-    };
+    }
 
     template <class T>
     FlagMaker& set(T* dest, const T& val) {
       flag->arity = 0;
       flag->handler = [=](std::vector<std::string> ss) { *dest = val; };
       return *this;
-    };
+    }
 
     FlagMaker& mkHashTypeFlag(HashType* ht);
   };
diff --git a/third_party/nix/src/libutil/util.cc b/third_party/nix/src/libutil/util.cc
index b13dd7e4f..0ad2c5114 100644
--- a/third_party/nix/src/libutil/util.cc
+++ b/third_party/nix/src/libutil/util.cc
@@ -35,8 +35,6 @@
 #include <sys/prctl.h>
 #endif
 
-__attribute__((weak));
-
 namespace nix {
 
 const std::string nativeSystem = SYSTEM;
diff --git a/third_party/nix/src/nix-build/nix-build.cc b/third_party/nix/src/nix-build/nix-build.cc
index 921fc2ba2..66947051b 100644
--- a/third_party/nix/src/nix-build/nix-build.cc
+++ b/third_party/nix/src/nix-build/nix-build.cc
@@ -23,8 +23,6 @@
 using namespace nix;
 using namespace std::string_literals;
 
-__attribute__((weak));
-
 /* Recreate the effect of the perl shellwords function, breaking up a
  * string into arguments like a shell word, including escapes
  */