diff --git a/core/decoder.sv b/core/decoder.sv
index 2a7dd3632..4948512db 100644
--- a/core/decoder.sv
+++ b/core/decoder.sv
@@ -171,8 +171,12 @@ module decoder
                 // DRET
                 12'b111_1011_0010: begin
                   instruction_o.op = ariane_pkg::DRET;
-                  // check that we are in debug mode when executing this instruction
-                  illegal_instr = (!debug_mode_i) ? 1'b1 : illegal_instr;
+                  if (CVA6Cfg.DebugEn) begin
+                    // check that we are in debug mode when executing this instruction
+                    illegal_instr = (!debug_mode_i) ? 1'b1 : illegal_instr;
+                  end else begin
+                    illegal_instr = 1'b1;
+                  end
                 end
                 // WFI
                 12'b1_0000_0101: begin