diff --git a/lib/rfnoc/blocks/rfnoc_block_radio/noc_shell_radio.v b/lib/rfnoc/blocks/rfnoc_block_radio/noc_shell_radio.v
index da0d7d0..63140dd 100644
--- a/lib/rfnoc/blocks/rfnoc_block_radio/noc_shell_radio.v
+++ b/lib/rfnoc/blocks/rfnoc_block_radio/noc_shell_radio.v
@@ -12,10 +12,16 @@
 //
 // Parameters:
 //
-//   THIS_PORTID : Control crossbar port to which this block is connected
-//   CHDR_W      : AXIS-CHDR data bus width
-//   MTU         : Maximum transmission unit (i.e., maximum packet size in
-//                 CHDR words is 2**MTU).
+//   THIS_PORTID  : Control crossbar port to which this block is connected
+//   CHDR_W       : AXIS-CHDR data bus width
+//   CTRL_CLK_IDX : The index of the control clock for this block. This is used
+//                  to populate the backend interface, from where UHD can query
+//                  the clock index and thus auto-deduct which clock is used.
+//   TB_CLK_IDX   : The index of the timebase clock for this block. This is used
+//                  to populate the backend interface, from where UHD can query
+//                  the clock index and thus auto-deduct which clock is used.
+//   MTU          : Maximum transmission unit (i.e., maximum packet size in
+//                  CHDR words is 2**MTU).
 //
 
 `default_nettype none
@@ -24,6 +30,8 @@
 module noc_shell_radio #(
   parameter [9:0] THIS_PORTID     = 10'd0,
   parameter       CHDR_W          = 64,
+  parameter [5:0] CTRL_CLK_IDX    = 6'h3F,
+  parameter [5:0] TB_CLK_IDX      = 6'h3F,
   parameter [5:0] MTU             = 10,
   parameter       NUM_PORTS       = 2,
   parameter       NIPC            = 1,
@@ -146,6 +154,8 @@ module noc_shell_radio #(
     .NUM_DATA_I    (0+NUM_PORTS),
     .NUM_DATA_O    (0+NUM_PORTS),
     .CTRL_FIFOSIZE ($clog2(512)),
+    .CTRL_CLK_IDX  (CTRL_CLK_IDX),
+    .TB_CLK_IDX    (TB_CLK_IDX),
     .MTU           (MTU)
   ) backend_iface_i (
     .rfnoc_chdr_clk       (rfnoc_chdr_clk),
diff --git a/lib/rfnoc/blocks/rfnoc_block_radio/rfnoc_block_radio.v b/lib/rfnoc/blocks/rfnoc_block_radio/rfnoc_block_radio.v
index 2fc8c57..6834b53 100644
--- a/lib/rfnoc/blocks/rfnoc_block_radio/rfnoc_block_radio.v
+++ b/lib/rfnoc/blocks/rfnoc_block_radio/rfnoc_block_radio.v
@@ -22,14 +22,16 @@
 
 
 module rfnoc_block_radio #(
-  parameter THIS_PORTID      = 0,
-  parameter CHDR_W           = 64,
-  parameter NIPC             = 1,
-  parameter ITEM_W           = 32,
-  parameter NUM_PORTS        = 2,
-  parameter MTU              = 10,
-  parameter PERIPH_BASE_ADDR = 20'h80000,
-  parameter PERIPH_ADDR_W    = 19
+  parameter THIS_PORTID           = 0,
+  parameter CHDR_W                = 64,
+  parameter NIPC                  = 1,
+  parameter ITEM_W                = 32,
+  parameter NUM_PORTS             = 2,
+  parameter MTU                   = 10,
+  parameter PERIPH_BASE_ADDR      = 20'h80000,
+  parameter PERIPH_ADDR_W         = 19,
+  parameter [5:0] CTRL_CLK_IDX    = 6'h3F,
+  parameter [5:0] TB_CLK_IDX      = 6'h3F
 ) (
   //---------------------------------------------------------------------------
   // AXIS CHDR Port
@@ -166,6 +168,8 @@ module rfnoc_block_radio #(
   noc_shell_radio #(
     .THIS_PORTID     (THIS_PORTID),
     .CHDR_W          (CHDR_W),
+    .CTRL_CLK_IDX    (CTRL_CLK_IDX),
+    .TB_CLK_IDX      (TB_CLK_IDX),
     .MTU             (MTU),
     .NUM_PORTS       (NUM_PORTS),
     .NIPC            (NIPC),