diff --git a/ariane.sv b/ariane.sv
index 06c1636e1..a0846a500 100644
--- a/ariane.sv
+++ b/ariane.sv
@@ -114,6 +114,7 @@ module ariane
         .illegal_c_insn_id_o ( illegal_c_insn_id_o     ),
         .pc_if_o             ( pc_if_o                 ),
         .pc_id_o             ( pc_id_o                 ),
+        .ex_o                ( exception_o             ),
         .boot_addr_i         ( boot_addr_i             )
     );
 
@@ -129,7 +130,7 @@ module ariane
         .instruction_i       ( instr_rdata_id_o    ),
         .instruction_valid_i ( instr_valid_id_o    ),
         .pc_if_i             ( pc_if_o             ), // PC from if
-        .ex_i                ( '{default: 0}       ), // exception from if
+        .ex_i                ( exception_o         ), // exception from if
         .ready_o             ( ready_o             ),
         .operator_o          ( operator_o          ),
         .operand_a_o         ( operand_a_o         ),
diff --git a/decoder.sv b/decoder.sv
index 72d1801da..188f6d25e 100644
--- a/decoder.sv
+++ b/decoder.sv
@@ -41,7 +41,6 @@ module decoder (
         imm_select = NOIMM;
         illegal_instr_o = 1'b0;
         instruction_o.valid = 1'b0;
-        instruction_o.ex = ex_i;
         instruction_o.fu = NONE;
         instruction_o.op = ADD;
         instruction_o.rs1 = 5'b0;
@@ -108,7 +107,9 @@ module decoder (
                         default: illegal_instr_o = 1'b1;
                       endcase
                 end
-
+                // --------------------------------
+                // Reg-Immediate Operations
+                // --------------------------------
                 OPCODE_OPIMM: begin
                     instruction_o.fu  = ALU;
                     imm_select = IIMM;
@@ -214,7 +215,9 @@ module decoder (
             endcase
         end
     end
-
+    // --------------------------------
+    // Sign extend immediate
+    // --------------------------------
     always_comb begin : sign_extend
         imm_i_type  = { {52 {instruction_i[31]}}, instruction_i[31:20] };
         imm_iz_type = {  52'b0, instruction_i[31:20] };
@@ -229,7 +232,7 @@ module decoder (
         imm_vs_type = { {58 {instruction_i[24]}}, instruction_i[24:20], instruction_i[25] };
         imm_vu_type = { 58'b0, instruction_i[24:20], instruction_i[25] };
 
-        //  NOIMM, PCIMM, IIMM, SIMM, BIMM, BIMM, UIMM, JIMM
+        // NOIMM, PCIMM, IIMM, SIMM, BIMM, BIMM, UIMM, JIMM
         // select immediate
         case (imm_select)
             PCIMM: begin
@@ -262,5 +265,15 @@ module decoder (
             end
         endcase
     end
+    // --------------------------------
+    // Exception handling
+    // --------------------------------
+    always_comb begin : exception_handling
+        instruction_o.ex = ex_i;
 
+        if (~ex_i.valid && illegal_instr_o) begin
+            instruction_o.ex.valid = 1'b1;
+            instruction_o.ex.cause = ILLEGAL_INSTR;
+        end
+    end
 endmodule
\ No newline at end of file
diff --git a/id_stage.sv b/id_stage.sv
index 4d6dc1077..38195e63a 100644
--- a/id_stage.sv
+++ b/id_stage.sv
@@ -140,5 +140,4 @@ module id_stage #(
         .we_a_i              (we_a_i             )
     );
 
-
 endmodule
\ No newline at end of file
diff --git a/if_stage.sv b/if_stage.sv
index 13c85420e..168e69f6b 100644
--- a/if_stage.sv
+++ b/if_stage.sv
@@ -49,6 +49,7 @@ module if_stage (
     output logic                   illegal_c_insn_id_o,   // compressed decoder thinks this is an invalid instruction
     output logic [63:0]            pc_if_o,
     output logic [63:0]            pc_id_o,
+    output exception               ex_o,
 
     input  logic [63:0]            boot_addr_i
 );
@@ -184,6 +185,7 @@ module if_stage (
               illegal_c_insn_id_o   <= 1'b0;
               is_compressed_id_o    <= 1'b0;
               pc_id_o               <= '0;
+              ex_o                  <= '{default: 0};
             end
           else
             begin
@@ -195,6 +197,9 @@ module if_stage (
                   illegal_c_insn_id_o <= illegal_c_insn;
                   is_compressed_id_o  <= instr_compressed_int;
                   pc_id_o             <= pc_if_o;
+                  ex_o.epc            <= pc_if_o;
+                  ex_o.cause          <= 64'b0; // TODO: Output exception
+                  ex_o.valid          <= 1'b0;  // TODO: Output exception
               end else if (clear_instr_valid_i) begin
                 instr_valid_id_o    <= 1'b0;
               end
diff --git a/include/ariane_pkg.svh b/include/ariane_pkg.svh
index 1d89df43d..ecc0001d9 100644
--- a/include/ariane_pkg.svh
+++ b/include/ariane_pkg.svh
@@ -73,7 +73,6 @@ package ariane_pkg;
         logic           valid;    // is the result valid
         logic           use_imm;  // should we use the immediate as operand b?
         logic           use_pc;   // set if we need to use the PC as operand A, PC from exception
-        // logic [63:0]    imm;       // maybe we can get this into the results field
         exception       ex;       // exception has occurred
     } scoreboard_entry;
 
@@ -154,4 +153,18 @@ package ariane_pkg;
       PRIV_LVL_U = 2'b00
     } priv_lvl_t;
 
+    // ----------------------
+    // Exception Cause Codes
+    // ----------------------
+    localparam INSTR_ADDR_MISALIGNED = 64'h0;
+    localparam INSTR_ACCESS_FAULT    = 64'h1;
+    localparam ILLEGAL_INSTR         = 64'h2;
+    localparam BREAKPOINT            = 64'h3;
+    localparam LD_ADDR_MISALIGNED    = 64'h4;
+    localparam LD_ACCESS_FAULT       = 64'h5;
+    localparam ST_ADDR_MISALIGNED    = 64'h6;
+    localparam ST_ACCESS_FAULT       = 64'h7;
+    localparam ENV_CALL_UMODE        = 64'h8;
+    localparam ENV_CALL_SMODE        = 64'h9;
+    localparam ENV_CALL_MMODE        = 64'hB;
 endpackage