diff --git a/CMakeLists.txt b/CMakeLists.txt
index e808fa80..90f48ffa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -338,6 +338,13 @@ target_include_directories(fmt-header-only ${FMT_SYSTEM_HEADERS_ATTRIBUTE} INTER
   $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
   $<INSTALL_INTERFACE:${FMT_INC_DIR}>)
 
+option(FMT_FILE_DESCRIPTORS "Disable this if your system does not provide numeric file descriptors" ON)
+mark_as_advanced(FMT_FILE_DESCRIPTORS)
+if (NOT FMT_FILE_DESCRIPTORS)
+  target_compile_definitions(fmt PUBLIC FMT_HAS_FILE_DESCRIPTORS=0)
+  target_compile_definitions(fmt-header-only INTERFACE FMT_HAS_FILE_DESCRIPTORS=0)
+endif ()
+
 # Install targets.
 if (FMT_INSTALL)
   include(CMakePackageConfigHelpers)
diff --git a/include/fmt/os.h b/include/fmt/os.h
index 2126424d..676ab112 100644
--- a/include/fmt/os.h
+++ b/include/fmt/os.h
@@ -19,6 +19,17 @@
 
 #include "format.h"
 
+// Some operating systems do not implement numeric file descriptors.
+// If set to 0, functions that rely on file descriptors will not be defined.
+#ifndef FMT_HAS_FILE_DESCRIPTORS
+#  define FMT_HAS_FILE_DESCRIPTORS 1
+#endif
+
+// FCNTL requires file descriptors.
+#if FMT_HAS_FILE_DESCRIPTORS == 0
+#  define FMT_USE_FCNTL 0
+#endif
+
 #ifndef FMT_USE_FCNTL
 // UWP doesn't provide _pipe.
 #  if FMT_HAS_INCLUDE("winapifamily.h")
@@ -222,7 +233,9 @@ class buffered_file {
   // Returns the pointer to a FILE object representing this file.
   FILE* get() const noexcept { return file_; }
 
+#if FMT_HAS_FILE_DESCRIPTORS
   FMT_API int descriptor() const;
+#endif
 
   void vprint(string_view format_str, format_args args) {
     fmt::vprint(file_, format_str, args);
diff --git a/src/os.cc b/src/os.cc
index bca410e9..33202f5b 100644
--- a/src/os.cc
+++ b/src/os.cc
@@ -181,6 +181,7 @@ void buffered_file::close() {
     FMT_THROW(system_error(errno, FMT_STRING("cannot close file")));
 }
 
+#if FMT_HAS_FILE_DESCRIPTORS
 int buffered_file::descriptor() const {
 #ifdef fileno  // fileno is a macro on OpenBSD so we cannot use FMT_POSIX_CALL.
   int fd = fileno(file_);
@@ -191,6 +192,7 @@ int buffered_file::descriptor() const {
     FMT_THROW(system_error(errno, FMT_STRING("cannot get file descriptor")));
   return fd;
 }
+#endif  // FMT_HAS_FILE_DESCRIPTORS
 
 #if FMT_USE_FCNTL
 #  ifdef _WIN32