diff --git a/pkgs/development/python-modules/islpy/default.nix b/pkgs/development/python-modules/islpy/default.nix
index afa1cf15e467..c748d527a554 100644
--- a/pkgs/development/python-modules/islpy/default.nix
+++ b/pkgs/development/python-modules/islpy/default.nix
@@ -46,10 +46,10 @@ buildPythonPackage rec {
   dontUseCmakeConfigure = true;
 
   cmakeFlags = [
-    "-DUSE_SHIPPED_ISL=OFF"
-    "-DUSE_BARVINOK=OFF"
-    "-DISL_INC_DIRS:LIST='${lib.getDev isl}/include'"
-    "-DISL_LIB_DIRS:LIST='${lib.getLib isl}/lib'"
+    (lib.cmakeBool "USE_SHIPPED_ISL" false)
+    (lib.cmakeBool "USE_BARVINOK" false)
+    (lib.cmakeOptionType "list" "ISL_INC_DIRS" "${lib.getDev isl}/include")
+    (lib.cmakeOptionType "list" "ISL_LIB_DIRS" "${lib.getLib isl}/lib")
   ];
 
   # Force resolving the package from $out to make generated ext files usable by tests