diff --git a/pkgs/development/tools/parsing/flex/2.5.35.nix b/pkgs/development/tools/parsing/flex/2.5.35.nix
index 1062a361413..3e40ddee9d9 100644
--- a/pkgs/development/tools/parsing/flex/2.5.35.nix
+++ b/pkgs/development/tools/parsing/flex/2.5.35.nix
@@ -17,10 +17,11 @@ stdenv.mkDerivation rec {
     "ac_cv_func_realloc_0_nonnull=yes"
   ];
 
-  meta = {
+  meta = with stdenv.lib; {
     branch = "2.5.35";
     homepage = http://flex.sourceforge.net/;
     description = "A fast lexical analyser generator";
-    platforms = stdenv.lib.platforms.unix;
+    license = licenses.bsd2;
+    platforms = platforms.unix;
   };
 }
diff --git a/pkgs/development/tools/parsing/flex/2.6.1.nix b/pkgs/development/tools/parsing/flex/2.6.1.nix
index 954c2bbcb24..81685b6ee66 100644
--- a/pkgs/development/tools/parsing/flex/2.6.1.nix
+++ b/pkgs/development/tools/parsing/flex/2.6.1.nix
@@ -26,9 +26,10 @@ stdenv.mkDerivation rec {
     substituteInPlace Makefile.in --replace "tests" " ";
   '';
 
-  meta = {
+  meta = with stdenv.lib; {
     homepage = https://github.com/westes/flex;
     description = "A fast lexical analyser generator";
-    platforms = stdenv.lib.platforms.unix;
+    license = licenses.bsd2;
+    platforms = platforms.unix;
   };
 }
diff --git a/pkgs/development/tools/parsing/flex/default.nix b/pkgs/development/tools/parsing/flex/default.nix
index 17323a06cc1..2a91baa80b3 100644
--- a/pkgs/development/tools/parsing/flex/default.nix
+++ b/pkgs/development/tools/parsing/flex/default.nix
@@ -41,9 +41,10 @@ stdenv.mkDerivation rec {
 
   dontDisableStatic = stdenv.buildPlatform != stdenv.hostPlatform;
 
-  meta = {
+  meta = with stdenv.lib; {
     homepage = https://github.com/westes/flex;
     description = "A fast lexical analyser generator";
-    platforms = stdenv.lib.platforms.unix;
+    license = licenses.bsd2;
+    platforms = platforms.unix;
   };
 }