diff --git a/src/sqlite-cli.nix b/src/sqlite-cli.nix
index 81de94f..c17572c 100644
--- a/src/sqlite-cli.nix
+++ b/src/sqlite-cli.nix
@@ -59,12 +59,12 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   makeFlags =
-    (coreInitExt.passthru.makeFlags or [ ])
+    (if coreInitExt == null then [ ] else coreInitExt.passthru.extraMakeFlags)
     ++ map (opt: "OPTIONS+=${lib.escapeShellArg opt}") featureFlags
     ++ [
       "sqlite3"
     ];
 
   env.NIX_CFLAGS_LINK = lib.optionalString features.ENABLE_FTS5 "-lm";
-  env.NIX_LDFLAGS = lib.concatStringsSep " " (coreInitExt.passthru.extraLDFLAGS or [ ]);
+  env.NIX_LDFLAGS = lib.concatStringsSep " " (if coreInitExt == null then [ ] else coreInitExt.passthru.extraLDFLAGS);
 })
diff --git a/src/sqlite.nix b/src/sqlite.nix
index b6d1685..1d3348a 100644
--- a/src/sqlite.nix
+++ b/src/sqlite.nix
@@ -55,19 +55,18 @@ stdenv.mkDerivation (finalAttrs: {
     "--${if static then "disable" else "enable"}-shared"
     "--${if static then "enable" else "disable"}-static"
     "--${if amalgamate then "enable" else "disable"}-amalgamation"
-
   ] ++ lib.optional features.ENABLE_ICU [
     "--enable-icu-collations"
     "--with-icu-config=${lib.getExe' icu.dev "icu-config"}"
   ];
 
   makeFlags =
-    (coreInitExt.passthru.makeFlags or [ ])
+    (if coreInitExt == null then [ ] else coreInitExt.passthru.extraMakeFlags)
     ++ map (opt: "OPTIONS+=${lib.escapeShellArg opt}") featureFlags
     ++ [
       (if static then "lib" else "so")
     ];
 
   env.NIX_CFLAGS_LINK = lib.optionalString features.ENABLE_FTS5 "-lm";
-  env.NIX_LDFLAGS = lib.concatStringsSep " " (coreInitExt.passthru.extraLDFLAGS or [ ]);
+  env.NIX_LDFLAGS = lib.concatStringsSep " " (if coreInitExt == null then [ ] else coreInitExt.passthru.extraLDFLAGS);
 })