diff --git a/stage0/astgen.c b/stage0/astgen.c
index 32efc99c20..27f9af76ec 100644
--- a/stage0/astgen.c
+++ b/stage0/astgen.c
@@ -3605,7 +3605,7 @@ static uint32_t builtinCall(
         AstData nd = tree->nodes.datas[node];
         uint32_t typeof_inst
             = makeBlockInst(ag, ZIR_INST_TYPEOF_BUILTIN, gz, node);
-        GenZir typeof_scope = makeSubBlock(gz, &gz->base);
+        GenZir typeof_scope = makeSubBlock(gz, scope);
         typeof_scope.is_comptime = false;
         typeof_scope.is_typeof = true;
         typeof_scope.c_import = false;
@@ -4293,6 +4293,63 @@ static uint32_t builtinCallMultiArg(GenZir* gz, Scope* scope, ResultLoc rl,
             gz, ZIR_INST_SHUFFLE, node, payload_index);
         return rvalue(gz, rl, result, node);
     }
+    // @TypeOf multi-arg (AstGen.zig:9120-9146).
+    if (name_len == 6 && memcmp(source + name_start, "TypeOf", 6) == 0) {
+        // Reserve extra space: 3 (TypeOfPeer payload) + param_count (refs).
+        uint32_t payload_size = 3; // src_node, body_len, body_index
+        ensureExtraCapacity(ag, payload_size + param_count);
+        uint32_t payload_index = ag->extra_len;
+        ag->extra_len += payload_size + param_count;
+        uint32_t args_index = payload_index + payload_size;
+
+        // Create the extended instruction (AstGen.zig:9124).
+        uint32_t typeof_inst = ag->inst_len;
+        ensureInstCapacity(ag, 1);
+        ag->inst_tags[typeof_inst] = ZIR_INST_EXTENDED;
+        ZirInstData tdata;
+        memset(&tdata, 0, sizeof(tdata));
+        tdata.extended.opcode = (uint16_t)ZIR_EXT_TYPEOF_PEER;
+        tdata.extended.small = (uint16_t)param_count;
+        tdata.extended.operand = payload_index;
+        ag->inst_datas[typeof_inst] = tdata;
+        ag->inst_len++;
+        gzAppendInstruction(gz, typeof_inst);
+
+        // Create sub-block scope (AstGen.zig:9126-9128).
+        GenZir typeof_scope = makeSubBlock(gz, scope);
+        typeof_scope.is_comptime = false;
+
+        // Evaluate each arg (AstGen.zig:9129-9132).
+        for (uint32_t i = 0; i < param_count; i++) {
+            uint32_t param_ref = reachableExpr(
+                &typeof_scope, &typeof_scope.base, RL_NONE_VAL,
+                params[i], node);
+            ag->extra[args_index + i] = param_ref;
+        }
+
+        // Add break_inline (AstGen.zig:9133).
+        addBreak(&typeof_scope, ZIR_INST_BREAK_INLINE,
+            typeof_inst, ZIR_REF_VOID_VALUE,
+            (int32_t)node - (int32_t)gz->decl_node_index);
+
+        // Get body and fill in payload (AstGen.zig:9135-9141).
+        uint32_t raw_len = gzInstructionsLen(&typeof_scope);
+        const uint32_t* body = gzInstructionsSlice(&typeof_scope);
+        uint32_t body_len = countBodyLenAfterFixups(ag, body, raw_len);
+
+        ag->extra[payload_index + 0]
+            = (uint32_t)((int32_t)node - (int32_t)gz->decl_node_index);
+        ag->extra[payload_index + 1] = body_len;
+        ag->extra[payload_index + 2] = ag->extra_len;
+
+        // Append body with fixups (AstGen.zig:9142-9143).
+        ensureExtraCapacity(ag, body_len);
+        for (uint32_t j = 0; j < raw_len; j++)
+            appendPossiblyRefdBodyInst(ag, body[j]);
+
+        gzUnstack(&typeof_scope);
+        return rvalue(gz, rl, typeof_inst + ZIR_REF_START_INDEX, node);
+    }
     // clang-format on
 
     // TODO: handle other multi-arg builtins.