diff --git a/src/amd/compiler/aco_optimizer.cpp b/src/amd/compiler/aco_optimizer.cpp
index aa9fad589b3..9d6219037de 100644
--- a/src/amd/compiler/aco_optimizer.cpp
+++ b/src/amd/compiler/aco_optimizer.cpp
@@ -2260,9 +2260,16 @@ bool combine_add_sub_b2i(opt_ctx& ctx, aco_ptr<Instruction>& instr, aco_opcode n
          }
          ctx.uses[instr->operands[i].tempId()]--;
          new_instr->definitions[0] = instr->definitions[0];
-         new_instr->definitions[1] =
-            instr->definitions.size() == 2 ? instr->definitions[1] :
-            Definition(ctx.program->allocateTmp(ctx.program->lane_mask));
+         if (instr->definitions.size() == 2) {
+            new_instr->definitions[1] = instr->definitions[1];
+         } else {
+            new_instr->definitions[1] =
+               Definition(ctx.program->allocateTmp(ctx.program->lane_mask));
+            /* Make sure the uses vector is large enough and the number of
+             * uses properly initialized to 0.
+             */
+            ctx.uses.push_back(0);
+         }
          new_instr->definitions[1].setHint(vcc);
          new_instr->operands[0] = Operand(0u);
          new_instr->operands[1] = instr->operands[!i];
diff --git a/src/amd/compiler/tests/test_optimizer.cpp b/src/amd/compiler/tests/test_optimizer.cpp
index 4bb5898e236..f43ae731072 100644
--- a/src/amd/compiler/tests/test_optimizer.cpp
+++ b/src/amd/compiler/tests/test_optimizer.cpp
@@ -119,6 +119,12 @@ BEGIN_TEST(optimize.cndmask)
       Temp xor_a = bld.vop2(aco_opcode::v_xor_b32, bld.def(v1), inputs[0], subbrev);
       writeout(3, bld.vop2(aco_opcode::v_and_b32, bld.def(v1), xor_a, subbrev));
 
+      //! v1: %res4 = v_cndmask_b32 0, %a, %c
+      //! p_unit_test 4, %res4
+      Temp cndmask = bld.vop2_e64(aco_opcode::v_cndmask_b32, bld.def(v1), Operand(0u), Operand(1u), Operand(inputs[2]));
+      Temp sub = bld.vsub32(bld.def(v1), Operand(0u), cndmask);
+      writeout(4, bld.vop2(aco_opcode::v_and_b32, bld.def(v1), Operand(inputs[0]), sub));
+
       finish_opt_test();
    }
 END_TEST