diff --git a/pkgs/applications/graphics/tesseract/tesseract3.nix b/pkgs/applications/graphics/tesseract/tesseract3.nix
index 4d3a97ade7dd..ffe3cbc7039e 100644
--- a/pkgs/applications/graphics/tesseract/tesseract3.nix
+++ b/pkgs/applications/graphics/tesseract/tesseract3.nix
@@ -47,7 +47,7 @@ stdenv.mkDerivation rec {
     opencl-headers
   ];
 
-  LIBLEPT_HEADERSDIR = "${leptonica}/include";
+  env.LIBLEPT_HEADERSDIR = "${leptonica}/include";
 
   meta = {
     description = "OCR engine";