diff --git a/include/fmt/base.h b/include/fmt/base.h
index a733a918..ec2326e0 100644
--- a/include/fmt/base.h
+++ b/include/fmt/base.h
@@ -1678,12 +1678,13 @@ template <typename... T> struct arg_pack {};
 template <typename Char, int NUM_ARGS, int NUM_NAMED_ARGS, bool DYNAMIC_NAMES>
 class format_string_checker {
  private:
-  type types_[max_of(1, NUM_ARGS)];
-  named_arg_info<Char> named_args_[max_of(1, NUM_NAMED_ARGS)];
+  type types_[static_cast<size_t>(max_of(1, NUM_ARGS))];
+  named_arg_info<Char>
+      named_args_[static_cast<size_t>(max_of(1, NUM_NAMED_ARGS))];
   compile_parse_context<Char> context_;
 
   using parse_func = auto (*)(parse_context<Char>&) -> const Char*;
-  parse_func parse_funcs_[max_of(1, NUM_ARGS)];
+  parse_func parse_funcs_[static_cast<size_t>(max_of(1, NUM_ARGS))];
 
  public:
   template <typename... T>
@@ -2338,8 +2339,9 @@ template <typename Context, int NUM_ARGS, int NUM_NAMED_ARGS,
           unsigned long long DESC>
 struct named_arg_store {
   // args_[0].named_args points to named_args to avoid bloating format_args.
-  arg_t<Context, NUM_ARGS> args[1 + NUM_ARGS];
-  named_arg_info<typename Context::char_type> named_args[NUM_NAMED_ARGS];
+  arg_t<Context, NUM_ARGS> args[static_cast<size_t>(1 + NUM_ARGS)];
+  named_arg_info<typename Context::char_type>
+      named_args[static_cast<size_t>(NUM_NAMED_ARGS)];
 
   template <typename... T>
   FMT_CONSTEXPR FMT_ALWAYS_INLINE named_arg_store(T&... values)
@@ -2370,10 +2372,10 @@ template <typename Context, int NUM_ARGS, int NUM_NAMED_ARGS,
           unsigned long long DESC>
 struct format_arg_store {
   // +1 to workaround a bug in gcc 7.5 that causes duplicated-branches warning.
-  using type =
-      conditional_t<NUM_NAMED_ARGS == 0,
-                    arg_t<Context, NUM_ARGS>[max_of(1, NUM_ARGS)],
-                    named_arg_store<Context, NUM_ARGS, NUM_NAMED_ARGS, DESC>>;
+  using type = conditional_t<
+      NUM_NAMED_ARGS == 0,
+      arg_t<Context, NUM_ARGS>[static_cast<size_t>(max_of(1, NUM_ARGS))],
+      named_arg_store<Context, NUM_ARGS, NUM_NAMED_ARGS, DESC>>;
   type args;
 };
 
diff --git a/include/fmt/format.h b/include/fmt/format.h
index 5aac87e4..6a0b5398 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -1225,7 +1225,8 @@ FMT_CONSTEXPR auto do_format_base2e(int base_bits, Char* out, UInt value,
   out += size;
   do {
     const char* digits = upper ? "0123456789ABCDEF" : "0123456789abcdef";
-    unsigned digit = static_cast<unsigned>(value & ((1 << base_bits) - 1));
+    unsigned digit = static_cast<unsigned>(
+        value & ((static_cast<UInt>(1) << base_bits) - 1));
     *--out = static_cast<Char>(base_bits < 4 ? static_cast<char>('0' + digit)
                                              : digits[digit]);
   } while ((value >>= base_bits) != 0);
@@ -2017,7 +2018,7 @@ FMT_CONSTEXPR FMT_INLINE auto write_int(OutputIt out, write_int_arg<T> arg,
                                         const format_specs& specs) -> OutputIt {
   static_assert(std::is_same<T, uint32_or_64_or_128_t<T>>::value, "");
 
-  constexpr int buffer_size = num_bits<T>();
+  constexpr size_t buffer_size = num_bits<T>();
   char buffer[buffer_size];
   if (is_constant_evaluated()) fill_n(buffer, buffer_size, '\0');
   const char* begin = nullptr;