diff --git a/src/nix-daemon/nix-daemon.cc b/src/nix-daemon/nix-daemon.cc
index aaae691e9..1d0ff701f 100644
--- a/src/nix-daemon/nix-daemon.cc
+++ b/src/nix-daemon/nix-daemon.cc
@@ -692,6 +692,10 @@ static PeerInfo getPeerInfo(int remote)
 
 #elif defined(LOCAL_PEERCRED)
 
+#if !defined(SOL_LOCAL)
+#define SOL_LOCAL 0
+#endif
+
     xucred cred;
     socklen_t credLen = sizeof(cred);
     if (getsockopt(remote, SOL_LOCAL, LOCAL_PEERCRED, &cred, &credLen) == -1)