diff --git a/include/multipart_parser.hpp b/include/multipart_parser.hpp
index 924ee8d..9d55f3a 100644
--- a/include/multipart_parser.hpp
+++ b/include/multipart_parser.hpp
@@ -239,7 +239,7 @@
         return static_cast<char>(c | 0x20);
     }
 
-    inline bool isBoundaryChar(char c) const
+    bool isBoundaryChar(char c) const
     {
         return boundaryIndex[static_cast<unsigned char>(c)];
     }