diff --git a/ChangeLog b/ChangeLog
index 154eaf1105..23dab6aa0b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+Sat Jun  7 22:13:42 2014  Benoit Daloze  <eregontp@gmail.com>
+
+	* numeric.c (do_coerce): Add a warning when an exception is raised
+	  or an invalid value is returned in #coerce called by
+	  numeric comparison operators and the exception
+	  thrown by the caller has no information on the failure.
+	  In the next release such exception should not be rescued or
+	  should be the cause of the caller exception. nil is accepted
+	  as the "no possible coercion" return value. See #7688.
+
+	* test/ruby/test_numeric.rb: Add corresponding test.
+
 Sat Jun  7 18:15:33 2014  Benoit Daloze  <eregontp@gmail.com>
 
 	* numeric.c (bit_coerce): remove constant parameter `err'
diff --git a/numeric.c b/numeric.c
index 86de28eb6c..f61b1349a6 100644
--- a/numeric.c
+++ b/numeric.c
@@ -251,6 +251,12 @@ coerce_rescue(VALUE *x)
     return Qnil;		/* dummy */
 }
 
+static VALUE
+coerce_rescue_quiet(VALUE *x)
+{
+    return Qundef;
+}
+
 static int
 do_coerce(VALUE *x, VALUE *y, int err)
 {
@@ -266,10 +272,18 @@ do_coerce(VALUE *x, VALUE *y, int err)
 	return FALSE;
     }
 
-    ary = rb_rescue(coerce_body, (VALUE)a, err ? coerce_rescue : 0, (VALUE)a);
+    ary = rb_rescue(coerce_body, (VALUE)a, err ? coerce_rescue : coerce_rescue_quiet, (VALUE)a);
+    if (ary == Qundef) {
+	rb_warn("Numerical comparison operators will no more rescue exceptions of #coerce");
+	rb_warn("in the next release. Return nil in #coerce if the coercion is impossible.");
+	return FALSE;
+    }
     if (!RB_TYPE_P(ary, T_ARRAY) || RARRAY_LEN(ary) != 2) {
 	if (err) {
 	    rb_raise(rb_eTypeError, "coerce must return [x, y]");
+	} else if (!NIL_P(ary)) {
+	    rb_warn("Bad return value for #coerce, called by numerical comparison operators.");
+	    rb_warn("#coerce must return [x, y]. The next release will raise an error for this.");
 	}
 	return FALSE;
     }
diff --git a/test/ruby/test_numeric.rb b/test/ruby/test_numeric.rb
index 674e869473..b42509dd1a 100644
--- a/test/ruby/test_numeric.rb
+++ b/test/ruby/test_numeric.rb
@@ -59,6 +59,23 @@ class TestNumeric < Test::Unit::TestCase
     end
     assert_equal(-1, -a)
 
+    bug7688 = '[ruby-core:51389] [Bug #7688]'
+    DummyNumeric.class_eval do
+      remove_method :coerce
+      def coerce(x); raise StandardError; end
+    end
+    assert_raise_with_message(TypeError, /can't be coerced into /) { 1 + a }
+    warn = /will no more rescue exceptions of #coerce.+ in the next release/m
+    assert_warn(warn, bug7688) { assert_raise(ArgumentError) { 1 < a } }
+
+    DummyNumeric.class_eval do
+      remove_method :coerce
+      def coerce(x); :bad_return_value; end
+    end
+    assert_raise_with_message(TypeError, "coerce must return [x, y]") { 1 + a }
+    warn = /Bad return value for #coerce.+next release will raise an error/m
+    assert_warn(warn, bug7688) { assert_raise(ArgumentError) { 1 < a } }
+
   ensure
     DummyNumeric.class_eval do
       remove_method :coerce