diff --git a/ompi/mca/pml/ob1/pml_ob1_irecv.c b/ompi/mca/pml/ob1/pml_ob1_irecv.c
index e6504e34ebd..29128ea7a38 100644
--- a/ompi/mca/pml/ob1/pml_ob1_irecv.c
+++ b/ompi/mca/pml/ob1/pml_ob1_irecv.c
@@ -3,7 +3,7 @@
  * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
  *                         University Research and Technology
  *                         Corporation.  All rights reserved.
- * Copyright (c) 2004-2014 The University of Tennessee and The University
+ * Copyright (c) 2004-2015 The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
  * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
@@ -29,6 +29,13 @@
 #include "ompi/peruse/peruse-internal.h"
 #include "ompi/message/message.h"
 
+/**
+ * Single usage request. As we allow recursive calls to recv
+ * (from the request completion callback), we cannot rely on
+ * using a global request. Thus, once a recv acquires ownership
+ * this global request, it should set it to NULL to prevent
+ * the reuse until the first user completes.
+ */
 mca_pml_ob1_recv_request_t *mca_pml_ob1_recvreq = NULL;
 
 int mca_pml_ob1_irecv_init(void *addr,
@@ -96,15 +103,13 @@ int mca_pml_ob1_recv(void *addr,
 
 #if !OMPI_ENABLE_THREAD_MULTIPLE
     recvreq = mca_pml_ob1_recvreq;
+    mca_pml_ob1_recvreq = NULL;
     if( OPAL_UNLIKELY(NULL == recvreq) )
 #endif  /* !OMPI_ENABLE_THREAD_MULTIPLE */
         {
             MCA_PML_OB1_RECV_REQUEST_ALLOC(recvreq);
             if (NULL == recvreq)
                 return OMPI_ERR_TEMP_OUT_OF_RESOURCE;
-#if !OMPI_ENABLE_THREAD_MULTIPLE
-            mca_pml_ob1_recvreq = recvreq;
-#endif  /* !OMPI_ENABLE_THREAD_MULTIPLE */
         }
 
     MCA_PML_OB1_RECV_REQUEST_INIT(recvreq, addr, count, datatype,
@@ -126,7 +131,12 @@ int mca_pml_ob1_recv(void *addr,
 #if OMPI_ENABLE_THREAD_MULTIPLE
     MCA_PML_OB1_RECV_REQUEST_RETURN(recvreq);
 #else
-    mca_pml_ob1_recv_request_fini (recvreq);
+    if( NULL != mca_pml_ob1_recvreq ) {
+        MCA_PML_OB1_RECV_REQUEST_RETURN(recvreq);
+    } else {
+        mca_pml_ob1_recv_request_fini (recvreq);
+        mca_pml_ob1_recvreq = recvreq;
+    }
 #endif
 
     return rc;
diff --git a/ompi/mca/pml/ob1/pml_ob1_isend.c b/ompi/mca/pml/ob1/pml_ob1_isend.c
index 5de0c89d8a4..dba3c22875c 100644
--- a/ompi/mca/pml/ob1/pml_ob1_isend.c
+++ b/ompi/mca/pml/ob1/pml_ob1_isend.c
@@ -29,6 +29,13 @@
 #include "pml_ob1_recvreq.h"
 #include "ompi/peruse/peruse-internal.h"
 
+/**
+ * Single usage request. As we allow recursive calls (as an
+ * example from the request completion callback), we cannot rely
+ * on using a global request. Thus, once a send acquires ownership
+ * of this global request, it should set it to NULL to prevent
+ * the reuse until the first user completes.
+ */
 mca_pml_ob1_send_request_t *mca_pml_ob1_sendreq = NULL;
 
 int mca_pml_ob1_isend_init(const void *buf,
@@ -217,15 +224,13 @@ int mca_pml_ob1_send(const void *buf,
 
 #if !OMPI_ENABLE_THREAD_MULTIPLE
     sendreq = mca_pml_ob1_sendreq;
+    mca_pml_ob1_sendreq = NULL;
     if( OPAL_UNLIKELY(NULL == sendreq) )
 #endif  /* !OMPI_ENABLE_THREAD_MULTIPLE */
         {
             MCA_PML_OB1_SEND_REQUEST_ALLOC(comm, dst, sendreq);
             if (NULL == sendreq)
                 return OMPI_ERR_TEMP_OUT_OF_RESOURCE;
-#if !OMPI_ENABLE_THREAD_MULTIPLE
-            mca_pml_ob1_sendreq = sendreq;
-#endif  /* !OMPI_ENABLE_THREAD_MULTIPLE */
         }
     sendreq->req_send.req_base.req_proc = dst_proc;
     sendreq->rdma_frag = NULL;
@@ -251,7 +256,12 @@ int mca_pml_ob1_send(const void *buf,
 #if OMPI_ENABLE_THREAD_MULTIPLE
     MCA_PML_OB1_SEND_REQUEST_RETURN(sendreq);
 #else
-    mca_pml_ob1_send_request_fini (sendreq);
+    if( NULL != mca_pml_ob1_sendreq ) {
+        MCA_PML_OB1_SEND_REQUEST_RETURN(sendreq);
+    } else {
+        mca_pml_ob1_send_request_fini (sendreq);
+        mca_pml_ob1_sendreq = sendreq;
+    }
 #endif
 
     return rc;