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)