diff --git a/CHANGELOG.md b/CHANGELOG.md
index 75ed059c4..6ea190f79 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
 
 ### Changed
+- `axi_err_slv`: Add optional parameter to define data returned by read response.  The parameter
+  defaults to a 64-bit value, so buses with data width larger than or equal to 64 bit see an
+  additional 32-bit value in error responses compared to the prior version.  Other than that, this
+  change is fully backward compatible.
 
 ### Fixed
 
diff --git a/src/axi_err_slv.sv b/src/axi_err_slv.sv
index 3a1356e51..b3a8b9cd1 100644
--- a/src/axi_err_slv.sv
+++ b/src/axi_err_slv.sv
@@ -14,12 +14,14 @@
 // it.  This module optionally supports ATOPs if the `ATOPs` parameter is set.
 
 module axi_err_slv #(
-  parameter int unsigned    AxiIdWidth  = 0,                    // AXI ID Width
-  parameter type            req_t       = logic,                // AXI 4 request struct, with atop field
-  parameter type            resp_t      = logic,                // AXI 4 response struct
-  parameter axi_pkg::resp_t Resp        = axi_pkg::RESP_DECERR, // Error generated by this slave.
-  parameter bit             ATOPs       = 1'b1,                 // Activate support for ATOPs.  Set to 1 if this slave could ever get an atomic AXI transaction.
-  parameter int unsigned    MaxTrans    = 1                     // Maximum # of accepted transactions before stalling
+  parameter int unsigned          AxiIdWidth  = 0,                    // AXI ID Width
+  parameter type                  req_t       = logic,                // AXI 4 request struct, with atop field
+  parameter type                  resp_t      = logic,                // AXI 4 response struct
+  parameter axi_pkg::resp_t       Resp        = axi_pkg::RESP_DECERR, // Error generated by this slave.
+  parameter int unsigned          RespWidth   = 32'd64,               // Data response width, gets zero extended or truncated to r.data.
+  parameter logic [RespWidth-1:0] RespData    = 64'hCA11AB1EBADCAB1E, // Hexvalue for data return value
+  parameter bit                   ATOPs       = 1'b1,                 // Activate support for ATOPs.  Set to 1 if this slave could ever get an atomic AXI transaction.
+  parameter int unsigned          MaxTrans    = 1                     // Maximum # of accepted transactions before stalling
 ) (
   input  logic  clk_i,   // Clock
   input  logic  rst_ni,  // Asynchronous reset active low
@@ -188,7 +190,7 @@ module axi_err_slv #(
     // r_channel
     err_resp.r        = '0;
     err_resp.r.id     = r_fifo_data.id;
-    err_resp.r.data   = 32'hBADCAB1E;
+    err_resp.r.data   = RespData;
     err_resp.r.resp   = Resp;
     err_resp.r_valid  = 1'b0;
     // control