diff --git a/build.sh b/build.sh
index 0dbc460..79a7532 100755
--- a/build.sh
+++ b/build.sh
@@ -8,7 +8,7 @@ ADDITIONAL_ARGS=${@:2}
 INPUT_FILE=`realpath $1`
 INPUT_DIR=`dirname $INPUT_FILE`
 METADATA_FILE="$INPUT_DIR/metadata.yaml"
-OUTPUT_FILE="$INPUT_DIR/output.pdf"
+export OUTPUT_FILE="$INPUT_DIR/output.pdf"
 
 INPUT_FILES="$INPUT_FILE"
 
diff --git a/word-count.lua b/word-count.lua
index 3606331..3b577d5 100644
--- a/word-count.lua
+++ b/word-count.lua
@@ -1,7 +1,7 @@
 return {
     {
         Meta = function(meta)
-            local rawText = pandoc.pipe("pdftotext", {"output.pdf", "-"}, "")
+            local rawText = pandoc.pipe("pdftotext", {os.getenv("OUTPUT_FILE"), "-"}, "")
             meta["wordcount"] = pandoc.pipe("wc", {"-w"}, rawText)
             return meta
         end,