diff --git a/centipede/mutation_input.h b/centipede/mutation_input.h
index 1b0191b1..fd7009f7 100644
--- a/centipede/mutation_input.h
+++ b/centipede/mutation_input.h
@@ -19,6 +19,7 @@
 #ifndef THIRD_PARTY_CENTIPEDE_MUTATION_INPUT_H_
 #define THIRD_PARTY_CENTIPEDE_MUTATION_INPUT_H_
 
+#include <utility>
 #include <vector>
 
 #include "./centipede/execution_metadata.h"
@@ -44,7 +45,10 @@ inline std::vector<MutationInputRef> GetMutationInputRefsFromDataInputs(
     const std::vector<ByteArray> &inputs) {
   std::vector<MutationInputRef> results;
   results.reserve(inputs.size());
-  for (const auto &input : inputs) results.push_back({.data = input});
+  for (const auto &input : inputs) {
+    MutationInputRef result{input};
+    results.push_back(std::move(result));
+  }
   return results;
 }
 
diff --git a/centipede/pc_info_test.cc b/centipede/pc_info_test.cc
index 68ba411f..b395a584 100644
--- a/centipede/pc_info_test.cc
+++ b/centipede/pc_info_test.cc
@@ -22,7 +22,13 @@ namespace centipede {
 namespace {
 
 TEST(PCTableTest, SerializesAndDeserializesPCInfoSuccessfully) {
-  PCTable input = {{.pc = 0, .flags = 1}, {.pc = 2, .flags = 3}};
+  PCInfo input1, input2;
+  input1.pc = 0;
+  input1.flags = 1;
+  input2.pc = 2;
+  input2.flags = 3;
+
+  PCTable input = {input1, input2};
 
   std::stringstream stream;
   WritePcTable(input, stream);
diff --git a/centipede/periodic_action_test.cc b/centipede/periodic_action_test.cc
index 33bdeb60..771660fb 100644
--- a/centipede/periodic_action_test.cc
+++ b/centipede/periodic_action_test.cc
@@ -50,13 +50,13 @@ TEST(PeriodicActionTest, OnlyNudgedInvocations) {
   constexpr absl::Duration kDuration = absl::Seconds(3);
   constexpr absl::Duration kNudgeInterval = absl::Milliseconds(100);
   int count = 0;
+  PeriodicAction::Options options;
+  // Effectively disable periodic invocations: only `Nudge()` calls
+  // below will trigger them.
+  options.sleep_before_each = [](size_t) { return absl::InfiniteDuration(); };
   PeriodicAction action{
       [&count]() { ++count; },
-      {
-          // Effectively disable periodic invocations: only `Nudge()` calls
-          // below will trigger them.
-          .sleep_before_each = [](size_t) { return absl::InfiniteDuration(); },
-      },
+      std::move(options),
   };
   int expected_count = 0;
   const absl::Time end_time = absl::Now() + kDuration;
diff --git a/centipede/puzzles/pthread_exit_uint32_cmp_1.cc b/centipede/puzzles/pthread_exit_uint32_cmp_1.cc
index 3a79bdcf..228134f5 100644
--- a/centipede/puzzles/pthread_exit_uint32_cmp_1.cc
+++ b/centipede/puzzles/pthread_exit_uint32_cmp_1.cc
@@ -34,7 +34,8 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   struct ThreadArg {
     const uint8_t *data;
     size_t size;
-  } arg = {.data = data, .size = size};
+  };
+  ThreadArg arg = {data, size};
   auto pt_entry = +[](const ThreadArg *thread_arg) {
     uint32_t value, expected_value;
     if (thread_arg->size == sizeof(value)) {
diff --git a/centipede/resource_pool_test.cc b/centipede/resource_pool_test.cc
index 684fd38d..27da5d59 100644
--- a/centipede/resource_pool_test.cc
+++ b/centipede/resource_pool_test.cc
@@ -32,9 +32,10 @@ namespace centipede::perf {
 namespace {
 
 TEST(ResourcePoolTest, InvalidLeaseRequests) {
-  const RUsageMemory kQuota = {.mem_rss = 1000};
-  const RUsageMemory kZero = {.mem_rss = 0};
-  const RUsageMemory kEpsilon = {.mem_rss = 1};
+  RUsageMemory kQuota, kZero, kEpsilon;
+  kQuota.mem_rss = 1000;
+  kZero.mem_rss = 0;
+  kEpsilon.mem_rss = 1;
   ResourcePool pool{kQuota};
   {
     const auto lease = pool.AcquireLeaseBlocking({.amount = kZero});
diff --git a/centipede/reverse_pc_table.h b/centipede/reverse_pc_table.h
index 8d2d7244..becde1c5 100644
--- a/centipede/reverse_pc_table.h
+++ b/centipede/reverse_pc_table.h
@@ -61,9 +61,10 @@ class ReversePCTable {
     for (size_t idx = 0; idx < pc_table.size(); ++idx) {
       const auto &pc_info = pc_table[idx];
       if (pc_info.pc >= size_) __builtin_trap();  // TODO(kcc): use RunnerCheck.
-      table_[pc_info.pc] = {
-          .is_function_entry = pc_info.has_flag(PCInfo::kFuncEntry),
-          .pc_index = static_cast<uint32_t>(idx)};
+      PCGuard pc_guard;
+      pc_guard.is_function_entry = pc_info.has_flag(PCInfo::kFuncEntry);
+      pc_guard.pc_index = static_cast<uint32_t>(idx);
+      table_[pc_info.pc] = pc_guard;
     }
   }
 
@@ -80,8 +81,7 @@ class ReversePCTable {
 
  private:
   // A PCGuard object, such that IsValid() will return false.
-  static constexpr PCGuard kInvalidPCGuard = {
-      .is_function_entry = 0, .pc_index = PCGuard::kInvalidPcIndex};
+  static constexpr PCGuard kInvalidPCGuard = {0, PCGuard::kInvalidPcIndex};
 
   // We use size_ and table_ pointer instead of std::vector<> because
   // (1) we need ReversePCTable object to be accessible even after the