diff --git a/nimble/host/src/ble_hs_hci.c b/nimble/host/src/ble_hs_hci.c
index ea2e067ee..f9167ff0b 100644
--- a/nimble/host/src/ble_hs_hci.c
+++ b/nimble/host/src/ble_hs_hci.c
@@ -440,6 +440,24 @@ ble_hs_hci_frag_alloc(uint16_t frag_size, void *arg)
     return NULL;
 }
 
+/**
+ * Retrieves the total capacity of the ACL fragment pool (always 1).
+ */
+int
+ble_hs_hci_frag_num_mbufs(void)
+{
+    return ble_hs_hci_frag_mempool.mp_num_blocks;
+}
+
+/**
+ * Retrieves the the count of free buffers in the ACL fragment pool.
+ */
+int
+ble_hs_hci_frag_num_mbufs_free(void)
+{
+    return ble_hs_hci_frag_mempool.mp_num_free;
+}
+
 static struct os_mbuf *
 ble_hs_hci_acl_hdr_prepend(struct os_mbuf *om, uint16_t handle,
                            uint8_t pb_flag)
diff --git a/nimble/host/src/ble_hs_hci_priv.h b/nimble/host/src/ble_hs_hci_priv.h
index a152dde1e..dc4d676d3 100644
--- a/nimble/host/src/ble_hs_hci_priv.h
+++ b/nimble/host/src/ble_hs_hci_priv.h
@@ -262,6 +262,9 @@ int ble_hs_hci_cmd_build_le_set_phy(uint16_t conn_handle, uint8_t tx_phys_mask,
                                     uint8_t rx_phys_mask, uint16_t phy_opts,
                                     uint8_t *dst, int dst_len);
 
+int ble_hs_hci_frag_num_mbufs(void);
+int ble_hs_hci_frag_num_mbufs_free(void);
+
 #if MYNEWT_VAL(BLE_EXT_ADV)
 #endif
 
diff --git a/nimble/host/test/src/ble_hs_test_util.c b/nimble/host/test/src/ble_hs_test_util.c
index a63d02f68..af30b8fa6 100644
--- a/nimble/host/test/src/ble_hs_test_util.c
+++ b/nimble/host/test/src/ble_hs_test_util.c
@@ -1738,6 +1738,18 @@ ble_hs_test_util_mbuf_chain_len(const struct os_mbuf *om)
     return count;
 }
 
+static int
+ble_hs_test_util_num_mbufs(void)
+{
+    return os_msys_count() + ble_hs_hci_frag_num_mbufs();
+}
+
+static int
+ble_hs_test_util_num_mbufs_free(void)
+{
+    return os_msys_num_free() + ble_hs_hci_frag_num_mbufs_free();
+}
+
 struct os_mbuf *
 ble_hs_test_util_mbuf_alloc_all_but(int count)
 {
@@ -1787,7 +1799,7 @@ ble_hs_test_util_mbuf_count(const struct ble_hs_test_util_mbuf_params *params)
 
     ble_hs_process_rx_data_queue();
 
-    count = os_msys_num_free();
+    count = ble_hs_test_util_num_mbufs_free();
 
     if (params->prev_tx) {
         count += ble_hs_test_util_mbuf_chain_len(ble_hs_test_util_prev_tx_cur);
@@ -1838,7 +1850,7 @@ ble_hs_test_util_assert_mbufs_freed(
     }
 
     count = ble_hs_test_util_mbuf_count(params);
-    TEST_ASSERT(count == os_msys_count());
+    TEST_ASSERT(count == ble_hs_test_util_num_mbufs());
 }
 
 static int