diff --git a/include/spdlog/sinks/rotating_file_sink-inl.h b/include/spdlog/sinks/rotating_file_sink-inl.h
new file mode 100644
index 00000000..17a4ee93
--- /dev/null
+++ b/include/spdlog/sinks/rotating_file_sink-inl.h
@@ -0,0 +1,132 @@
+// Copyright(c) 2015-present Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include "spdlog/common.h"
+
+#include "spdlog/details/file_helper.h"
+#include "spdlog/details/null_mutex.h"
+#include "spdlog/fmt/fmt.h"
+
+#include <cerrno>
+#include <chrono>
+#include <ctime>
+#include <mutex>
+#include <string>
+#include <tuple>
+
+
+namespace spdlog {
+namespace sinks {
+
+template<typename Mutex>
+SPDLOG_INLINE rotating_file_sink<Mutex>::rotating_file_sink(
+    filename_t base_filename, std::size_t max_size, std::size_t max_files, bool rotate_on_open)
+    : base_filename_(std::move(base_filename))
+    , max_size_(max_size)
+    , max_files_(max_files)
+{
+    file_helper_.open(calc_filename(base_filename_, 0));
+    current_size_ = file_helper_.size(); // expensive. called only once
+    if (rotate_on_open && current_size_ > 0)
+    {
+        rotate_();
+    }
+}
+
+// calc filename according to index and file extension if exists.
+// e.g. calc_filename("logs/mylog.txt, 3) => "logs/mylog.3.txt".
+template<typename Mutex>
+SPDLOG_INLINE filename_t rotating_file_sink<Mutex>::calc_filename(const filename_t &filename, std::size_t index)
+{
+    typename std::conditional<std::is_same<filename_t::value_type, char>::value, fmt::memory_buffer, fmt::wmemory_buffer>::type w;
+    if (index != 0u)
+    {
+        filename_t basename, ext;
+        std::tie(basename, ext) = details::file_helper::split_by_extension(filename);
+        fmt::format_to(w, SPDLOG_FILENAME_T("{}.{}{}"), basename, index, ext);
+    }
+    else
+    {
+        fmt::format_to(w, SPDLOG_FILENAME_T("{}"), filename);
+    }
+    return fmt::to_string(w);
+}
+
+
+
+template<typename Mutex>
+SPDLOG_INLINE const filename_t &rotating_file_sink<Mutex>::filename() const
+{
+    return file_helper_.filename();
+}
+
+template<typename Mutex>
+SPDLOG_INLINE void rotating_file_sink<Mutex>::sink_it_(const details::log_msg &msg)
+{
+    fmt::memory_buffer formatted;
+    sink::formatter_->format(msg, formatted);
+    current_size_ += formatted.size();
+    if (current_size_ > max_size_)
+    {
+        rotate_();
+        current_size_ = formatted.size();
+    }
+    file_helper_.write(formatted);
+}
+
+template<typename Mutex>
+SPDLOG_INLINE void rotating_file_sink<Mutex>::flush_()
+{
+    file_helper_.flush();
+}
+
+// Rotate files:
+// log.txt -> log.1.txt
+// log.1.txt -> log.2.txt
+// log.2.txt -> log.3.txt
+// log.3.txt -> delete
+template<typename Mutex>
+SPDLOG_INLINE void rotating_file_sink<Mutex>::rotate_()
+{
+    using details::os::filename_to_str;
+    file_helper_.close();
+    for (auto i = max_files_; i > 0; --i)
+    {
+        filename_t src = calc_filename(base_filename_, i - 1);
+        if (!details::file_helper::file_exists(src))
+        {
+            continue;
+        }
+        filename_t target = calc_filename(base_filename_, i);
+
+        if (!rename_file(src, target))
+        {
+            // if failed try again after a small delay.
+            // this is a workaround to a windows issue, where very high rotation
+            // rates can cause the rename to fail with permission denied (because of antivirus?).
+            details::os::sleep_for_millis(100);
+            if (!rename_file(src, target))
+            {
+                file_helper_.reopen(true); // truncate the log file anyway to prevent it to grow beyond its limit!
+                current_size_ = 0;
+                throw spdlog_ex("rotating_file_sink: failed renaming " + filename_to_str(src) + " to " + filename_to_str(target), errno);
+            }
+        }
+    }
+    file_helper_.reopen(true);
+}
+
+// delete the target if exists, and rename the src file  to target
+// return true on success, false otherwise.
+template<typename Mutex>
+SPDLOG_INLINE bool rotating_file_sink<Mutex>::rename_file(const filename_t &src_filename, const filename_t &target_filename)
+{
+    // try to delete the target file in case it already exists.
+    (void)details::os::remove(target_filename);
+    return details::os::rename(src_filename, target_filename) == 0;
+}
+
+} // namespace sinks
+} // namespace spdlog
diff --git a/include/spdlog/sinks/rotating_file_sink.h b/include/spdlog/sinks/rotating_file_sink.h
index ab658532..0ce71a61 100644
--- a/include/spdlog/sinks/rotating_file_sink.h
+++ b/include/spdlog/sinks/rotating_file_sink.h
@@ -2,22 +2,16 @@
 // Distributed under the MIT License (http://opensource.org/licenses/MIT)
 
 #pragma once
-
 #ifndef SPDLOG_H
 #include "spdlog/spdlog.h"
 #endif
 
-#include "spdlog/details/file_helper.h"
-#include "spdlog/details/null_mutex.h"
-#include "spdlog/fmt/fmt.h"
 #include "spdlog/sinks/base_sink.h"
+#include "spdlog/details/file_helper.h"
 
-#include <cerrno>
 #include <chrono>
-#include <ctime>
 #include <mutex>
 #include <string>
-#include <tuple>
 
 namespace spdlog {
 namespace sinks {
@@ -29,60 +23,15 @@ template<typename Mutex>
 class rotating_file_sink final : public base_sink<Mutex>
 {
 public:
-    rotating_file_sink(filename_t base_filename, std::size_t max_size, std::size_t max_files, bool rotate_on_open = false)
-        : base_filename_(std::move(base_filename))
-        , max_size_(max_size)
-        , max_files_(max_files)
-    {
-        file_helper_.open(calc_filename(base_filename_, 0));
-        current_size_ = file_helper_.size(); // expensive. called only once
-        if (rotate_on_open && current_size_ > 0)
-        {
-            rotate_();
-        }
-    }
+    rotating_file_sink(filename_t base_filename, std::size_t max_size, std::size_t max_files, bool rotate_on_open = false);
+    static filename_t calc_filename(const filename_t &filename, std::size_t index);
+    const filename_t &filename() const;
 
-    // calc filename according to index and file extension if exists.
-    // e.g. calc_filename("logs/mylog.txt, 3) => "logs/mylog.3.txt".
-    static filename_t calc_filename(const filename_t &filename, std::size_t index)
-    {
-        typename std::conditional<std::is_same<filename_t::value_type, char>::value, fmt::memory_buffer, fmt::wmemory_buffer>::type w;
-        if (index != 0u)
-        {
-            filename_t basename, ext;
-            std::tie(basename, ext) = details::file_helper::split_by_extension(filename);
-            fmt::format_to(w, SPDLOG_FILENAME_T("{}.{}{}"), basename, index, ext);
-        }
-        else
-        {
-            fmt::format_to(w, SPDLOG_FILENAME_T("{}"), filename);
-        }
-        return fmt::to_string(w);
-    }
-
-    const filename_t &filename() const
-    {
-        return file_helper_.filename();
-    }
 
 protected:
-    void sink_it_(const details::log_msg &msg) override
-    {
-        fmt::memory_buffer formatted;
-        sink::formatter_->format(msg, formatted);
-        current_size_ += formatted.size();
-        if (current_size_ > max_size_)
-        {
-            rotate_();
-            current_size_ = formatted.size();
-        }
-        file_helper_.write(formatted);
-    }
+    void sink_it_(const details::log_msg &msg) override;
+    void flush_() override;
 
-    void flush_() override
-    {
-        file_helper_.flush();
-    }
 
 private:
     // Rotate files:
@@ -90,45 +39,11 @@ private:
     // log.1.txt -> log.2.txt
     // log.2.txt -> log.3.txt
     // log.3.txt -> delete
-    void rotate_()
-    {
-        using details::os::filename_to_str;
-        file_helper_.close();
-        for (auto i = max_files_; i > 0; --i)
-        {
-            filename_t src = calc_filename(base_filename_, i - 1);
-            if (!details::file_helper::file_exists(src))
-            {
-                continue;
-            }
-            filename_t target = calc_filename(base_filename_, i);
-
-            if (!rename_file(src, target))
-            {
-                // if failed try again after a small delay.
-                // this is a workaround to a windows issue, where very high rotation
-                // rates can cause the rename to fail with permission denied (because of antivirus?).
-                details::os::sleep_for_millis(100);
-                if (!rename_file(src, target))
-                {
-                    file_helper_.reopen(true); // truncate the log file anyway to prevent it to grow beyond its limit!
-                    current_size_ = 0;
-                    throw spdlog_ex(
-                        "rotating_file_sink: failed renaming " + filename_to_str(src) + " to " + filename_to_str(target), errno);
-                }
-            }
-        }
-        file_helper_.reopen(true);
-    }
+    void rotate_();
 
     // delete the target if exists, and rename the src file  to target
     // return true on success, false otherwise.
-    bool rename_file(const filename_t &src_filename, const filename_t &target_filename)
-    {
-        // try to delete the target file in case it already exists.
-        (void)details::os::remove(target_filename);
-        return details::os::rename(src_filename, target_filename) == 0;
-    }
+    bool rename_file(const filename_t &src_filename, const filename_t &target_filename);
 
     filename_t base_filename_;
     std::size_t max_size_;
@@ -160,3 +75,8 @@ inline std::shared_ptr<logger> rotating_logger_st(
     return Factory::template create<sinks::rotating_file_sink_st>(logger_name, filename, max_file_size, max_files, rotate_on_open);
 }
 } // namespace spdlog
+
+
+#ifdef SPDLOG_HEADER_ONLY
+#include "rotating_file_sink-inl.h"
+#endif
\ No newline at end of file
diff --git a/src/spdlog.cpp b/src/spdlog.cpp
index 60b18966..c5fbf8f0 100644
--- a/src/spdlog.cpp
+++ b/src/spdlog.cpp
@@ -31,6 +31,11 @@
 template class spdlog::sinks::base_sink<std::mutex>;
 template class spdlog::sinks::base_sink<spdlog::details::null_mutex>;
 
+#include "spdlog/sinks/rotating_file_sink.h"
+#include "spdlog/sinks/rotating_file_sink-inl.h"
+template class spdlog::sinks::rotating_file_sink<std::mutex>;
+template class spdlog::sinks::rotating_file_sink<spdlog::details::null_mutex>;
+
 #include "spdlog/details/registry.h"
 #include "spdlog/details/registry-inl.h"
 
@@ -62,7 +67,6 @@ template class spdlog::sinks::ansicolor_sink<spdlog::details::console_stderr, sp
 template void spdlog::details::fmt_helper::append_string_view(spdlog::string_view_t view, fmt::memory_buffer &dest);
 template spdlog::string_view_t spdlog::details::fmt_helper::to_string_view(const fmt::memory_buffer &buf) SPDLOG_NOEXCEPT;
 
-
 // Slightly modified version of fmt lib's format.cc source file.
 // Copyright (c) 2012 - 2016, Victor Zverovich
 // All rights reserved.