diff --git a/src/if_ruby.c b/src/if_ruby.c
index 90e814e..7e49906 100644
--- a/src/if_ruby.c
+++ b/src/if_ruby.c
@@ -31,6 +31,10 @@
 # define RUBYEXTERN extern
 #endif
 
+# if defined(DYNAMIC_RUBY_VER) && DYNAMIC_RUBY_VER >= 24
+ # define USE_RUBY_Integer
+#endif
+
 #ifdef DYNAMIC_RUBY
 /*
  * This is tricky.  In ruby.h there is (inline) function rb_class_of()
@@ -39,6 +43,9 @@
  */
 # define rb_cFalseClass		(*dll_rb_cFalseClass)
 # define rb_cFixnum		(*dll_rb_cFixnum)
+# if defined(USE_RUBY_Integer)
+# define rb_cInteger    (*dll_rb_cInteger)
+# endif
 # if defined(DYNAMIC_RUBY_VER) && DYNAMIC_RUBY_VER >= 20
 #  define rb_cFloat		(*dll_rb_cFloat)
 # endif
@@ -318,6 +325,9 @@
 static VALUE (*dll_rb_assoc_new) (VALUE, VALUE);
 VALUE *dll_rb_cFalseClass;
 VALUE *dll_rb_cFixnum;
+# if defined(USE_RUBY_Integer)
+VALUE *dll_rb_cInteger;
+# endif
 # if defined(DYNAMIC_RUBY_VER) && DYNAMIC_RUBY_VER >= 20
 VALUE *dll_rb_cFloat;
 # endif
@@ -505,6 +515,9 @@
     {"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},
+# endif
 # if defined(DYNAMIC_RUBY_VER) && DYNAMIC_RUBY_VER >= 20
     {"rb_cFloat", (RUBY_PROC*)&dll_rb_cFloat},
 # endif