diff --git a/src/core-init-ext.nix b/src/core-init-ext.nix
index 32738c1..bc9facd 100644
--- a/src/core-init-ext.nix
+++ b/src/core-init-ext.nix
@@ -107,7 +107,7 @@ in stdenv.mkDerivation (finalAttrs: {
       opts = [
         "-DSQLITE_EXTRA_INIT=core_init"
         "-DSQLITE_EXTRA_SHUTDOWN=core_shutdown"
-        "-DSQLITE_CUSTOM_INCLUDE=${placeholder "out"}/include/sqlite-core-init.h"
+        "-DSQLITE_CUSTOM_INCLUDE=${finalAttrs.finalPackage}/include/sqlite-core-init.h"
       ];
     in map (opt: "OPTIONS+=${lib.escapeShellArg opt}") opts;
   };