diff --git a/srsue/hdr/stack/mac/proc_bsr.h b/srsue/hdr/stack/mac/proc_bsr.h
index f64c65ea8..d7624be60 100644
--- a/srsue/hdr/stack/mac/proc_bsr.h
+++ b/srsue/hdr/stack/mac/proc_bsr.h
@@ -50,6 +50,9 @@ public:
 
   /* MUX calls BSR to let it generate a padding BSR if there is space in PDU */
   virtual bool generate_padding_bsr(uint32_t nof_padding_bytes, bsr_t* bsr) = 0;
+
+  /* MUX calls BSR to update buffer state of each LCG after all PDUs for this TTI have been packed */
+  virtual void update_bsr_tti_end(const bsr_t* bsr) = 0;
 };
 
 class bsr_proc : public srslte::timer_callback, public bsr_interface_mux
@@ -67,6 +70,7 @@ public:
   uint32_t get_buffer_state();
   bool     need_to_send_bsr_on_ul_grant(uint32_t grant_size, uint32_t total_data, bsr_t* bsr);
   bool     generate_padding_bsr(uint32_t nof_padding_bytes, bsr_t* bsr);
+  void     update_bsr_tti_end(const bsr_t* bsr);
 
 private:
   const static int QUEUE_STATUS_PERIOD_MS = 1000;
@@ -99,7 +103,7 @@ private:
   void     print_state();
   void     set_trigger(triggered_bsr_type_t new_trigger);
   void     update_new_data();
-  void     update_buffer_state();
+  void     update_old_buffer();
   bool     check_highest_channel();
   bool     check_new_data();
   bool     check_any_channel();
diff --git a/srsue/src/stack/mac/mux.cc b/srsue/src/stack/mac/mux.cc
index 30fe7c9bd..cb75b3617 100644
--- a/srsue/src/stack/mac/mux.cc
+++ b/srsue/src/stack/mac/mux.cc
@@ -293,6 +293,9 @@ uint8_t* mux::pdu_get(srslte::byte_buffer_t* payload, uint32_t pdu_sz)
     }
   }
 
+  // Update buffers in BSR procedure after packing entire TTI
+  bsr_procedure->update_bsr_tti_end(&bsr);
+
   // Generate MAC PDU and save to buffer
   uint8_t* ret = pdu_msg.write_packet(log_h);
   Info("%s\n", pdu_msg.to_string().c_str());
diff --git a/srsue/src/stack/mac/proc_bsr.cc b/srsue/src/stack/mac/proc_bsr.cc
index 99dadfe68..b15f2a6d1 100644
--- a/srsue/src/stack/mac/proc_bsr.cc
+++ b/srsue/src/stack/mac/proc_bsr.cc
@@ -198,7 +198,7 @@ void bsr_proc::update_new_data()
   }
 }
 
-void bsr_proc::update_buffer_state()
+void bsr_proc::update_old_buffer()
 {
   for (int i = 0; i < NOF_LCG; i++) {
     for (std::map<uint32_t, lcid_t>::iterator iter = lcgs[i].begin(); iter != lcgs[i].end(); ++iter) {
@@ -269,6 +269,24 @@ bool bsr_proc::generate_bsr(bsr_t* bsr, uint32_t pdu_space)
   return send_bsr;
 }
 
+/* After packing all UL PDUs for this TTI, the internal buffer state of the BSR procedure needs to be updated with what
+ * has actually been transmitted in each LCG. We don't ask RLC again as new SDUs could have queued up again. Currently
+ * we just get the updates per LCG. Since we are only interested when zero outstanding data has been reported, we
+ * currently just reset the buffer for each LCID of the LCG.
+ */
+void bsr_proc::update_bsr_tti_end(const bsr_t* bsr)
+{
+  std::lock_guard<std::mutex> lock(mutex);
+  for (uint32_t i = 0; i < NOF_LCG; i++) {
+    if (bsr->buff_size[i] == 0) {
+      for (std::map<uint32_t, lcid_t>::iterator iter = lcgs[i].begin(); iter != lcgs[i].end(); ++iter) {
+        // Reset buffer state for all LCIDs of that the LCG for which we reported no further data to transmit
+        iter->second.old_buffer = 0;
+      }
+    }
+  }
+}
+
 // Checks if Regular BSR must be assembled, as defined in 5.4.5
 // Padding BSR is assembled when called by mux_unit when UL dci is received
 // Periodic BSR is triggered by the expiration of the timers
@@ -288,7 +306,7 @@ void bsr_proc::step(uint32_t tti)
     set_trigger(REGULAR);
   }
 
-  update_buffer_state();
+  update_old_buffer();
 }
 
 char* bsr_proc::bsr_type_tostring(triggered_bsr_type_t type)