diff --git a/ChangeLog b/ChangeLog
index ad1704688a..dea7394c26 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon May 23 21:33:36 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* include/ruby/missing.h (isfinite): move from numeric.c.
+
 Mon May 23 21:09:06 2016  Kazuki Yamaguchi  <k@rhe.jp>
 
 	* ext/openssl/ossl.c (Init_openssl): Avoid reference to unset global
diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index c9afdf3e04..3ccad9a508 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -30,10 +30,6 @@
 #include <ieeefp.h>
 #endif
 
-#if !defined(HAVE_ISFINITE) && defined(HAVE_FINITE) && !defined(isfinite)
-# define isfinite(x) finite(x)
-#endif
-
 /* #define ENABLE_NUMERIC_STRING */
 
 #define MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, min, max) ( \
diff --git a/include/ruby/missing.h b/include/ruby/missing.h
index 97091606b0..3474ca256f 100644
--- a/include/ruby/missing.h
+++ b/include/ruby/missing.h
@@ -174,6 +174,13 @@ RUBY_EXTERN int isnan(double);
 # endif
 #endif
 
+#ifndef isfinite
+# ifndef HAVE_ISFINITE
+#   define HAVE_ISFINITE 1
+#   define isfinite(x) finite(x)
+# endif
+#endif
+
 #ifndef HAVE_NEXTAFTER
 RUBY_EXTERN double nextafter(double x, double y);
 #endif
diff --git a/numeric.c b/numeric.c
index 6523249697..6c8afe2ec0 100644
--- a/numeric.c
+++ b/numeric.c
@@ -24,14 +24,6 @@
 #include <ieeefp.h>
 #endif
 
-#if !defined HAVE_ISFINITE && !defined isfinite
-#if defined HAVE_FINITE && !defined finite && !defined _WIN32
-extern int finite(double);
-# define HAVE_ISFINITE 1
-# define isfinite(x) finite(x)
-#endif
-#endif
-
 /* use IEEE 64bit values if not defined */
 #ifndef FLT_RADIX
 #define FLT_RADIX 2