diff --git a/lib/licenses.nix b/lib/licenses.nix
index e88054134a3d..f22d1401410b 100644
--- a/lib/licenses.nix
+++ b/lib/licenses.nix
@@ -715,7 +715,12 @@ in mkLicense lset) ({
 
   ncsa = {
     spdxId = "NCSA";
-    fullName  = "University of Illinois/NCSA Open Source License";
+    fullName = "University of Illinois/NCSA Open Source License";
+  };
+
+  nlpl = {
+    spdxId = "NLPL";
+    fullName = "No Limit Public License";
   };
 
   nposl3 = {
diff --git a/pkgs/tools/networking/imapsync/default.nix b/pkgs/tools/networking/imapsync/default.nix
index 5604145a182e..0fb519ad5af7 100644
--- a/pkgs/tools/networking/imapsync/default.nix
+++ b/pkgs/tools/networking/imapsync/default.nix
@@ -65,7 +65,7 @@ stdenv.mkDerivation rec {
   meta = with lib; {
     description = "Mail folder synchronizer between IMAP servers";
     homepage = "https://imapsync.lamiral.info/";
-    license = licenses.wtfpl;
+    license = licenses.nlpl;
     maintainers = with maintainers; [ pSub ];
     platforms = platforms.unix;
   };