diff --git a/src/intel/compiler/brw/brw_opt_cmod_propagation.cpp b/src/intel/compiler/brw/brw_opt_cmod_propagation.cpp
index 496379fa8a8..0f66f379dbd 100644
--- a/src/intel/compiler/brw/brw_opt_cmod_propagation.cpp
+++ b/src/intel/compiler/brw/brw_opt_cmod_propagation.cpp
@@ -99,6 +99,17 @@ cmod_propagate_cmp_to_add(const intel_device_info *devinfo, brw_inst *inst)
    }
 
    foreach_inst_in_block_reverse_starting_from(brw_inst, scan_inst, inst) {
+      /* If either of the sources of the CMP is modified, the optimization
+       * cannot occur. This is the case even if the instruction modifying the
+       * value is an ADD of the appropriate form.
+       */
+      if (regions_overlap(scan_inst->dst, scan_inst->size_written,
+                          inst->src[0], inst->size_read(devinfo, 0)) ||
+          regions_overlap(scan_inst->dst, scan_inst->size_written,
+                          inst->src[1], inst->size_read(devinfo, 1))) {
+         break;
+      }
+
       if (scan_inst->opcode == BRW_OPCODE_ADD &&
           !scan_inst->predicate &&
           scan_inst->dst.is_contiguous() &&
diff --git a/src/intel/compiler/brw/test_opt_cmod_propagation.cpp b/src/intel/compiler/brw/test_opt_cmod_propagation.cpp
index c18b3f663eb..93d891be10e 100644
--- a/src/intel/compiler/brw/test_opt_cmod_propagation.cpp
+++ b/src/intel/compiler/brw/test_opt_cmod_propagation.cpp
@@ -693,6 +693,27 @@ TEST_F(cmod_propagation_test, subtract_delete_compare)
    EXPECT_SHADERS_MATCH(bld, exp);
 }
 
+TEST_F(cmod_propagation_test, subtract_no_delete_compare_write_between)
+{
+   brw_builder bld = make_shader();
+   brw_reg dest = vgrf(bld, BRW_TYPE_F);
+   brw_reg src0 = vgrf(bld, BRW_TYPE_F);
+
+   set_condmod(BRW_CONDITIONAL_L, bld.ADD(dest, src0, brw_imm_f(-1.0f)));
+   bld.MOV(src0, brw_imm_f(5.0));
+   bld.CMP(bld.null_reg_f(), src0, brw_imm_f(1.0f), BRW_CONDITIONAL_L);
+
+   /* = Before =
+    * 0: add.l.f0(8)     dest0:F src0:F  -1.0:F
+    * 1: mov(0)          src0:F  5.0:F
+    * 2: cmp.l.f0(8)     null:F  src0:F  1.0:F
+    *
+    * = After =
+    * No changes.
+    */
+   EXPECT_NO_PROGRESS(brw_opt_cmod_propagation, bld);
+}
+
 TEST_F(cmod_propagation_test, subtract_delete_compare_other_flag)
 {
    /* This test is the same as subtract_delete_compare but it explicitly used