diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 667dd2edb..85246ced6 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -35,7 +35,7 @@
 #endif
 
 
-extern char * * environ;
+extern char * * environ __attribute__((weak));
 
 
 namespace nix {
diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc
index a224d635d..f77de56ea 100755
--- a/src/nix-build/nix-build.cc
+++ b/src/nix-build/nix-build.cc
@@ -21,7 +21,7 @@
 using namespace nix;
 using namespace std::string_literals;
 
-extern char * * environ;
+extern char * * environ __attribute__((weak));
 
 /* Recreate the effect of the perl shellwords function, breaking up a
  * string into arguments like a shell word, including escapes
diff --git a/src/nix/command.cc b/src/nix/command.cc
index d62626c26..3651a9e9c 100644
--- a/src/nix/command.cc
+++ b/src/nix/command.cc
@@ -4,7 +4,7 @@
 #include "nixexpr.hh"
 #include "profiles.hh"
 
-extern char * * environ;
+extern char * * environ __attribute__((weak));
 
 namespace nix {