diff --git a/build.sh b/build.sh
index 2c2ec547dd617a40357beaa3c621869db02da321..806d5ef6d072e1c4e748f874482bf1c3b9c1384c 100755
--- a/build.sh
+++ b/build.sh
@@ -19,7 +19,7 @@ then
   mkdir "$fbxsdkdir"
   url=$(grep 'fbx.*fbxsdk' $reqsfile)
   file=${url##*/}
-  tar="${fbxsdkdir}/${f}"
+  tar="${fbxsdkdir}/${file}"
   curl -L -o "$tar" $url
   tar -xvzf "$tar" -C "$fbxsdkdir"
   printf "yes\nn\n" |"$fbxsdkdir"/fbx*fbxsdk_linux "$fbxsdkdir"
@@ -36,7 +36,7 @@ then
   mkdir "$fbxpydir"
   url=$(grep 'fbx.*fbxpythonbindings_linux' $reqsfile)
   file=${url##*/}
-  tar="${fbxpydir}/${f}"
+  tar="${fbxpydir}/${file}"
   curl -L -o "$tar" $url
   tar -xvzf "$tar" -C "$fbxpydir"
   printf "yes\nn\n"|"$fbxpydir"/fbx*fbxpythonbindings_linux "$fbxpydir"