diff --git a/pkgs/applications/editors/nano/default.nix b/pkgs/applications/editors/nano/default.nix
index 3d089c1cec19..f3a5a27bd366 100644
--- a/pkgs/applications/editors/nano/default.nix
+++ b/pkgs/applications/editors/nano/default.nix
@@ -36,6 +36,11 @@ in stdenv.mkDerivation rec {
     --sysconfdir=/etc
     ${optionalString (!enableNls) "--disable-nls"}
     ${optionalString enableTiny "--enable-tiny"}
+  ''
+  # Unclear why (perhaps an impurity?) but for some reason it decides that REG_ENHANCED is available
+  # during configure but then can't find it at build time.
+    + optionalString stdenv.isDarwin ''
+    nano_cv_flag_reg_extended=REG_EXTENDED
   '';
 
   postPatch = optionalString stdenv.isDarwin ''