diff --git a/ChangeLog b/ChangeLog
index 8a1c3c6153..5c3ed8b5c2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Tue Jun 25 21:26:00 2013  Kenta Murata  <mrkn@mrkn.jp>
+
+	* ext/bigdecimal/bigdecimal.c (BigMath_s_exp): Fix for the cases when
+	  the argument x is not a BigDecimal.
+	  This change is based on the patch made by Garth Snyder.
+	  [Fix GH-332] https://github.com/ruby/ruby/pull/332
+
 Tue Jun 25 20:36:31 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (big2ulong): "check" argument removed.
diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index ba8777635f..87587f81a0 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -2725,7 +2725,7 @@ BigMath_s_exp(VALUE klass, VALUE x, VALUE vprec)
     else if (vx == NULL) {
 	cannot_be_coerced_into_BigDecimal(rb_eArgError, x);
     }
-    RB_GC_GUARD(vx->obj);
+    x = RB_GC_GUARD(vx->obj);
 
     n = prec + rmpd_double_figures();
     negative = VpGetSign(vx) < 0;
diff --git a/test/bigdecimal/test_bigdecimal.rb b/test/bigdecimal/test_bigdecimal.rb
index 07c79a8874..5cbafdafd4 100644
--- a/test/bigdecimal/test_bigdecimal.rb
+++ b/test/bigdecimal/test_bigdecimal.rb
@@ -1276,11 +1276,35 @@ class TestBigDecimal < Test::Unit::TestCase
   end
 
   def test_BigMath_exp
-    n = 20
-    assert_in_epsilon(Math.exp(n), BigMath.exp(BigDecimal("20"), n))
-    assert_in_epsilon(Math.exp(40), BigMath.exp(BigDecimal("40"), n))
-    assert_in_epsilon(Math.exp(-n), BigMath.exp(BigDecimal("-20"), n))
-    assert_in_epsilon(Math.exp(-40), BigMath.exp(BigDecimal("-40"), n))
+    prec = 20
+    assert_in_epsilon(Math.exp(20), BigMath.exp(BigDecimal("20"), prec))
+    assert_in_epsilon(Math.exp(40), BigMath.exp(BigDecimal("40"), prec))
+    assert_in_epsilon(Math.exp(-20), BigMath.exp(BigDecimal("-20"), prec))
+    assert_in_epsilon(Math.exp(-40), BigMath.exp(BigDecimal("-40"), prec))
+  end
+
+  def test_BigMath_exp_with_float
+    prec = 20
+    assert_in_epsilon(Math.exp(20), BigMath.exp(20.0, prec))
+    assert_in_epsilon(Math.exp(40), BigMath.exp(40.0, prec))
+    assert_in_epsilon(Math.exp(-20), BigMath.exp(-20.0, prec))
+    assert_in_epsilon(Math.exp(-40), BigMath.exp(-40.0, prec))
+  end
+
+  def test_BigMath_exp_with_fixnum
+    prec = 20
+    assert_in_epsilon(Math.exp(20), BigMath.exp(20, prec))
+    assert_in_epsilon(Math.exp(40), BigMath.exp(40, prec))
+    assert_in_epsilon(Math.exp(-20), BigMath.exp(-20, prec))
+    assert_in_epsilon(Math.exp(-40), BigMath.exp(-40, prec))
+  end
+
+  def test_BigMath_exp_with_rational
+    prec = 20
+    assert_in_epsilon(Math.exp(20), BigMath.exp(Rational(40,2), prec))
+    assert_in_epsilon(Math.exp(40), BigMath.exp(Rational(80,2), prec))
+    assert_in_epsilon(Math.exp(-20), BigMath.exp(Rational(-40,2), prec))
+    assert_in_epsilon(Math.exp(-40), BigMath.exp(Rational(-80,2), prec))
   end
 
   def test_BigMath_exp_under_gc_stress