1 files changed, 14 insertions, 1 deletions
diff --git a/math.c b/math.c
index fe25c4c0a0..37d019bc70 100644
--- a/math.c
+++ b/math.c
@@ -15,7 +15,20 @@
 
 VALUE rb_mMath;
 
-#define Need_Float(x) (x) = rb_Float(x)
+static VALUE
+to_flo(VALUE x)
+{
+    if (!rb_obj_is_kind_of(x, rb_cNumeric)) {
+	rb_raise(rb_eTypeError, "can't convert %s into Float",
+		 NIL_P(x) ? "nil" :
+		 x == Qtrue ? "true" :
+		 x == Qfalse ? "false" :
+		 rb_obj_classname(x));
+    }
+    return rb_convert_type(x, T_FLOAT, "Float", "to_f");
+}
+
+#define Need_Float(x) (x) = to_flo(x)
 #define Need_Float2(x,y) do {\
     Need_Float(x);\
     Need_Float(y);\