diff --git a/appveyor.yml b/appveyor.yml
index cdf0ee1b..1dd4c405 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -74,6 +74,8 @@ install:
 
 - set /p commit=<symengine_version.txt
 - cd symengine-cpp
+- git config --add remote.origin.fetch "+refs/pull/*/head:refs/remotes/origin/pr/*"
+- git fetch
 - git checkout %commit%
 - mkdir build
 - cd build
diff --git a/bin/test_symengine_unix.sh b/bin/test_symengine_unix.sh
index 0c62b7d1..81245174 100644
--- a/bin/test_symengine_unix.sh
+++ b/bin/test_symengine_unix.sh
@@ -4,6 +4,8 @@ export MAKEFLAGS="-j2"
 
 git clone https://github.com/symengine/symengine symengine-cpp
 cd symengine-cpp
+git config --add remote.origin.fetch '+refs/pull/*/head:refs/remotes/origin/pr/*'
+git fetch
 export SOURCE_DIR=`pwd`
 git checkout `cat ../symengine_version.txt`
 cd ..
diff --git a/symengine/tests/test_pickling.py b/symengine/tests/test_pickling.py
index a51a3251..cefbbfb6 100644
--- a/symengine/tests/test_pickling.py
+++ b/symengine/tests/test_pickling.py
@@ -22,8 +22,15 @@ def __eq__(self, other):
             return False
         return self.name == other.name and self.attr == other.attr
 
+    def __ne__(self, other):
+        return not (self == other)
+
+    def __hash__(self, other):
+        return hash((self.__class__.__name__, self.name, self.attr))
+
 
 class MySymbol(MySymbolBase):
+
     def __reduce__(self):
         return (self.__class__, (self.name, self.attr))
 
@@ -31,11 +38,17 @@ def __reduce__(self):
 def test_pysymbol():
     a = MySymbol("hello", attr=1)
     b = pickle.loads(pickle.dumps(a + 2)) - 2
+    c = MySymbol("hello", attr=-1)
     try:
         assert a == b
+        assert type(a) == type(b)
+        assert a.attr == 1
+        assert b.attr == 1
+        assert b != c
     finally:
         a._unsafe_reset()
         b._unsafe_reset()
+        c._unsafe_reset()
 
     a = MySymbolBase("hello", attr=1)
     try:
diff --git a/symengine_version.txt b/symengine_version.txt
index 57395265..470f7b84 100644
--- a/symengine_version.txt
+++ b/symengine_version.txt
@@ -1 +1 @@
-8a3bc848cd8246a4c15eee9bddc15de0d1157812
+d10ee0be16d25f1e35d5cd31d6ac2788eb426833