diff --git a/pkgs/development/php-packages/memprof/default.nix b/pkgs/development/php-packages/memprof/default.nix
index 3834fd396ba7..9538529a680d 100644
--- a/pkgs/development/php-packages/memprof/default.nix
+++ b/pkgs/development/php-packages/memprof/default.nix
@@ -19,7 +19,12 @@ buildPecl {
     hash = "sha256-gq+txAU2Fw+Zm1aIu0lwPUHRqtccNcHFpp0fm3f7BnQ=";
   };
 
-  configureFlags = [ "--with-judy-dir=${judy}" ];
+  buildInputs = [
+    judy
+  ];
+  configureFlags = [
+    "--with-judy-dir=${lib.getDev judy}"
+  ];
 
   doCheck = true;