diff --git a/doc/manual/src/language/index.md b/doc/manual/src/language/index.md
index f9e9b9781..db34fde75 100644
--- a/doc/manual/src/language/index.md
+++ b/doc/manual/src/language/index.md
@@ -93,7 +93,7 @@ This is an incomplete overview of language features, by example.
 
    `"hello ${ { a = "world" }.a }"`
 
-   `"1 2 ${3}"`
+   `"1 2 ${toString 3}"`
 
    `"${pkgs.bash}/bin/sh"`
 
diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc
index 232440f74..d44694890 100644
--- a/src/libstore/build/local-derivation-goal.cc
+++ b/src/libstore/build/local-derivation-goal.cc
@@ -1637,6 +1637,22 @@ void setupSeccomp()
         seccomp_arch_add(ctx, SCMP_ARCH_ARM) != 0)
         printError("unable to add ARM seccomp architecture; this may result in spurious build failures if running 32-bit ARM processes");
 
+    if (nativeSystem == "mips64-linux" &&
+        seccomp_arch_add(ctx, SCMP_ARCH_MIPS) != 0)
+        printError("unable to add mips seccomp architecture");
+
+    if (nativeSystem == "mips64-linux" &&
+        seccomp_arch_add(ctx, SCMP_ARCH_MIPS64N32) != 0)
+        printError("unable to add mips64-*abin32 seccomp architecture");
+
+    if (nativeSystem == "mips64el-linux" &&
+        seccomp_arch_add(ctx, SCMP_ARCH_MIPSEL) != 0)
+        printError("unable to add mipsel seccomp architecture");
+
+    if (nativeSystem == "mips64el-linux" &&
+        seccomp_arch_add(ctx, SCMP_ARCH_MIPSEL64N32) != 0)
+        printError("unable to add mips64el-*abin32 seccomp architecture");
+
     /* Prevent builders from creating setuid/setgid binaries. */
     for (int perm : { S_ISUID, S_ISGID }) {
         if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(chmod), 1,