diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 0dac1377d..19250fe24 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"