diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ad1c90e..8b9b9420 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,10 @@
 Changelog
 ---------
 
+v3.1.1
+------
+- Bug fix for the pool objects on the recycling functionality.
+
 v3.1.0
 ------
 - A new high-performant, optimized implementation for the flat-combining synchronization technique. This new implementation provided by the Synch framework is written from the scratch.
diff --git a/benchmarks/clhstackbench.c b/benchmarks/clhstackbench.c
index f64eef01..8d114228 100644
--- a/benchmarks/clhstackbench.c
+++ b/benchmarks/clhstackbench.c
@@ -58,7 +58,7 @@ inline static Object pop(int pid) {
 #endif
     synchNonTSOFence();
     CLHUnlock(lock, pid);
-    synchRecycleObj(&pool_node, n);
+    if (n != NULL) synchRecycleObj(&pool_node, n);
 
     return result;
 }
diff --git a/libconcurrent/primitives/pool.c b/libconcurrent/primitives/pool.c
index 7772b8ce..a4b4a1b0 100644
--- a/libconcurrent/primitives/pool.c
+++ b/libconcurrent/primitives/pool.c
@@ -76,6 +76,9 @@ void *synchAllocObj(SynchPoolStruct *pool) {
 
 void synchRecycleObj(SynchPoolStruct *pool, void *obj) {
 #ifndef SYNCH_POOL_NODE_RECYCLING_DISABLE
+    if (obj == NULL)
+        return;
+
     SynchBlockObject *object = obj;
     object->next = pool->recycle_list;
     pool->recycle_list = object;
diff --git a/resources/Doxyfile b/resources/Doxyfile
index a4e2c485..e5ed27c1 100644
--- a/resources/Doxyfile
+++ b/resources/Doxyfile
@@ -38,7 +38,7 @@ PROJECT_NAME           = "The Synch framework"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = v3.1.0
+PROJECT_NUMBER         = v3.1.1
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a