diff --git a/src/libstore/normalise.cc b/src/libstore/normalise.cc
index 682ea2a80..d91e5ea26 100644
--- a/src/libstore/normalise.cc
+++ b/src/libstore/normalise.cc
@@ -7,6 +7,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <errno.h>
 
 #include "normalise.hh"
 #include "references.hh"
diff --git a/src/nix-env/profiles.cc b/src/nix-env/profiles.cc
index d47c528b2..1eeddf332 100644
--- a/src/nix-env/profiles.cc
+++ b/src/nix-env/profiles.cc
@@ -3,6 +3,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <errno.h>
 
 
 static bool cmpGensByNumber(const Generation & a, const Generation & b)