diff --git a/src/if_ruby.c b/src/if_ruby.c
index fc72d33..bc6edc7 100644
--- a/src/if_ruby.c
+++ b/src/if_ruby.c
@@ -514,9 +514,10 @@
 {
     {"rb_assoc_new", (RUBY_PROC*)&dll_rb_assoc_new},
     {"rb_cFalseClass", (RUBY_PROC*)&dll_rb_cFalseClass},
-    {"rb_cFixnum", (RUBY_PROC*)&dll_rb_cFixnum},
 # if defined(USE_RUBY_INTEGER)
     {"rb_cInteger", (RUBY_PROC*)&dll_rb_cInteger},
+# else
+    {"rb_cFixnum", (RUBY_PROC*)&dll_rb_cFixnum},
 # endif
 # if defined(DYNAMIC_RUBY_VER) && DYNAMIC_RUBY_VER >= 20
     {"rb_cFloat", (RUBY_PROC*)&dll_rb_cFloat},