diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 0dac1377de74b97263069e4e0df056452b14fea8..19250fe24a22ad3326eba470d43dd92be52551b1 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -59,8 +59,8 @@
 /* chroot-like behavior from Apple's sandbox */
 #if __APPLE__
     #define SANDBOX_ENABLED 1
-    #define DEFAULT_ALLOWED_IMPURE_PREFIXES "/System/Library /usr /dev /bin/sh"
     #define DARWIN_PREBUILD 1
+    #define DEFAULT_ALLOWED_IMPURE_PREFIXES "/System/Library /usr/lib /dev /bin/sh"
 #else
     #define SANDBOX_ENABLED 0
     #define DEFAULT_ALLOWED_IMPURE_PREFIXES "/bin" "/usr/bin"