diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
index 147062fe..3fbb8060 100644
--- a/include/fmt/format-inl.h
+++ b/include/fmt/format-inl.h
@@ -698,7 +698,7 @@ FMT_API bool grisu_format(Double value, buffer<char>& buf, int precision,
       buf.push_back('0');
     } else {
       exp = -precision;
-      buf.resize(precision);
+      buf.resize(to_unsigned(precision));
       std::uninitialized_fill_n(buf.data(), precision, '0');
     }
     return true;
diff --git a/src/posix.cc b/src/posix.cc
index 69c27819..79b8ecbe 100644
--- a/src/posix.cc
+++ b/src/posix.cc
@@ -12,7 +12,7 @@
 
 #include "fmt/posix.h"
 
-#include <limits.h>
+#include <climits>
 #include <sys/stat.h>
 #include <sys/types.h>
 
@@ -49,7 +49,7 @@
 namespace {
 #ifdef _WIN32
 // Return type of read and write functions.
-typedef int RWResult;
+using RWResult = int;
 
 // On Windows the count argument to read and write is unsigned, so convert
 // it from size_t preventing integer overflow.
@@ -58,7 +58,7 @@ inline unsigned convert_rwcount(std::size_t count) {
 }
 #else
 // Return type of read and write functions.
-typedef ssize_t RWResult;
+using RWResult = ssize_t;
 
 inline std::size_t convert_rwcount(std::size_t count) { return count; }
 #endif
@@ -138,7 +138,7 @@ long long file::size() const {
   unsigned long long long_size = size_upper;
   return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
 #else
-  typedef struct stat Stat;
+  using Stat = struct stat;
   Stat file_stat = Stat();
   if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
     FMT_THROW(system_error(errno, "cannot get file attributes"));