diff --git a/pkgs/build-support/rust/build-rust-package/default.nix b/pkgs/build-support/rust/build-rust-package/default.nix
index a1727c91ba36..40b7a6181232 100644
--- a/pkgs/build-support/rust/build-rust-package/default.nix
+++ b/pkgs/build-support/rust/build-rust-package/default.nix
@@ -150,21 +150,24 @@ stdenv.mkDerivation ((removeAttrs args [ "depsExtraArgs" "cargoUpdateHook" "carg
 
   strictDeps = true;
 
-  meta = {
-    # default to Rust's platforms
-    platforms = rustc.meta.platforms ++ [
-      # Platforms without host tools from
-      # https://doc.rust-lang.org/nightly/rustc/platform-support.html
-      "armv7a-darwin"
-      "armv5tel-linux" "armv7a-linux" "m68k-linux" "mips-linux"
-      "mips64-linux" "mipsel-linux" "mips64el-linux" "riscv32-linux"
-      "armv6l-netbsd" "mipsel-netbsd" "riscv64-netbsd"
-      "x86_64-redox"
-      "wasm32-wasi"
-    ];
-    badPlatforms = [
+  meta = meta // {
+    badPlatforms = meta.badPlatforms or [] ++ [
       # Rust is currently unable to target the n32 ABI
       lib.systems.inspect.patterns.isMips64n32
     ];
-  } // meta;
+  } // lib.optionalAttrs (rustc.meta ? platforms) {
+    # default to Rust's platforms
+    platforms = lib.intersectLists
+      meta.platforms or lib.platforms.all
+      (rustc.meta.platforms ++ [
+        # Platforms without host tools from
+        # https://doc.rust-lang.org/nightly/rustc/platform-support.html
+        "armv7a-darwin"
+        "armv5tel-linux" "armv7a-linux" "m68k-linux" "mips-linux"
+        "mips64-linux" "mipsel-linux" "mips64el-linux" "riscv32-linux"
+        "armv6l-netbsd" "mipsel-netbsd" "riscv64-netbsd"
+        "x86_64-redox"
+        "wasm32-wasi"
+      ]);
+  };
 })