1 files changed, 1 insertions, 1 deletions
diff --git a/string.c b/string.c
index 0aa2e6c52c..44f3131e7a 100644
--- a/string.c
+++ b/string.c
@@ -781,7 +781,7 @@ rb_str_free(VALUE str)
     }
 }
 
-size_t
+RUBY_FUNC_EXPORTED size_t
 rb_str_memsize(VALUE str)
 {
     if (!STR_EMBED_P(str) && !STR_SHARED_P(str)) {