diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index 0a262eb2..059627c8 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -75,6 +75,16 @@
# endif
#endif
+#ifdef SPDLOG_USE_STD_FORMAT
+ #define SPDLOG_CONSTEXPR_FUNC constexpr
+#else // Being built with fmt
+ #if FMT_USE_CONSTEXPR
+ #define SPDLOG_CONSTEXPR_FUNC FMT_CONSTEXPR
+ #else
+ #define SPDLOG_CONSTEXPR_FUNC inline
+ #endif
+#endif
+
#if defined(__GNUC__) || defined(__clang__)
# define SPDLOG_DEPRECATED __attribute__((deprecated))
#elif defined(_MSC_VER)