diff --git a/src/spesh/dump.c b/src/spesh/dump.c
index e7d6bcd204..874950ef51 100644
--- a/src/spesh/dump.c
+++ b/src/spesh/dump.c
@@ -400,10 +400,12 @@ static void dump_facts(MVMThreadContext *tc, DumpStr *ds, MVMSpeshGraph *g) {
         for (j = 0; j < num_facts; j++) {
             MVMint32 usages = g->facts[i][j].usages;
             MVMint32 flags  = g->facts[i][j].flags;
+            MVMuint16 deopt_required = g->facts[i][j].deopt_required;
             if (i < 10) append(ds, " ");
             if (j < 10) append(ds, " ");
             if (flags || g->facts[i][j].dead_writer || g->facts[i][j].writer && g->facts[i][j].writer->info->opcode == MVM_SSA_PHI) {
-                appendf(ds, "    r%d(%d): usages=%d, flags=%-5d", i, j, usages, flags);
+                appendf(ds, "    r%d(%d): usages=%d%s, flags=%-5d", i, j, usages,
+                    deopt_required ? "+deopt" : "", flags);
                 if (flags & 1) {
                     append(ds, " KnTyp");
                 }
diff --git a/src/spesh/facts.c b/src/spesh/facts.c
index e34e8edece..ee14892d3b 100644
--- a/src/spesh/facts.c
+++ b/src/spesh/facts.c
@@ -477,7 +477,9 @@ static void add_bb_facts(MVMThreadContext *tc, MVMSpeshGraph *g, MVMSpeshBB *bb,
             if ((is_phi && i > 0)
                 || (!is_phi && (ins->info->operands[i] & MVM_operand_rw_mask) == MVM_operand_read_reg)) {
                 MVMSpeshFacts *facts = &(g->facts[ins->operands[i].reg.orig][ins->operands[i].reg.i]);
-                facts->usages += facts->deopt_idx == cur_deopt_idx ? 1 : 2;
+                facts->usages++;
+                if (facts->deopt_idx != cur_deopt_idx)
+                    facts->deopt_required = 1;
             }
 
             /* Writes need the current deopt index and the writing instruction
@@ -747,3 +749,10 @@ void MVM_spesh_facts_discover(MVMThreadContext *tc, MVMSpeshGraph *g, MVMSpeshPl
     add_bb_facts(tc, g, g->entry, p, -1);
     tweak_block_handler_usage(tc, g);
 }
+
+/* Checks if an operand is in use, either by having a non-zero usage count or
+ * being required for deopt. */
+MVMint32 MVM_spesh_facts_is_used(MVMThreadContext *tc, MVMSpeshGraph *g, MVMSpeshOperand operand) {
+   MVMSpeshFacts *facts = MVM_spesh_get_facts(tc, g, operand);
+   return facts->usages > 0 || facts->deopt_required;
+}
diff --git a/src/spesh/facts.h b/src/spesh/facts.h
index d42afe3d9c..33839e9a69 100644
--- a/src/spesh/facts.h
+++ b/src/spesh/facts.h
@@ -31,8 +31,11 @@ struct MVMSpeshFacts {
     /* The log guard the facts depend on, if any. */
     MVMuint32 log_guard;
 
+    /* Does the instruction need to be preserved for the sake of deopt? */
+    MVMuint16 deopt_required;
+
     /* Has the instruction that wrote this value been deleted? */
-    MVMuint32 dead_writer;
+    MVMuint16 dead_writer;
 };
 
 /* Various fact flags. */
@@ -57,3 +60,4 @@ void MVM_spesh_facts_depend(MVMThreadContext *tc, MVMSpeshGraph *g,
     MVMSpeshFacts *target, MVMSpeshFacts *source);
 void MVM_spesh_facts_object_facts(MVMThreadContext *tc, MVMSpeshGraph *g,
     MVMSpeshOperand tgt, MVMObject *obj);
+MVMint32 MVM_spesh_facts_is_used(MVMThreadContext *tc, MVMSpeshGraph *g, MVMSpeshOperand operand);
diff --git a/src/spesh/optimize.c b/src/spesh/optimize.c
index 762ea8f8e5..92ea9bf53e 100644
--- a/src/spesh/optimize.c
+++ b/src/spesh/optimize.c
@@ -2416,8 +2416,7 @@ static void eliminate_dead_ins(MVMThreadContext *tc, MVMSpeshGraph *g) {
                 while (ins) {
                     MVMSpeshIns *prev = ins->prev;
                     if (ins->info->opcode == MVM_SSA_PHI) {
-                        MVMSpeshFacts *facts = get_facts_direct(tc, g, ins->operands[0]);
-                        if (facts->usages == 0) {
+                        if (!MVM_spesh_facts_is_used(tc, g, ins->operands[0])) {
                             /* Remove this phi. */
                             MVM_spesh_manipulate_delete_ins(tc, g, bb, ins);
                             death = 1;
@@ -2426,8 +2425,7 @@ static void eliminate_dead_ins(MVMThreadContext *tc, MVMSpeshGraph *g) {
                     else if (ins->info->pure) {
                         /* Sanity check to make sure it's a write reg as first operand. */
                         if ((ins->info->operands[0] & MVM_operand_rw_mask) == MVM_operand_write_reg) {
-                            MVMSpeshFacts *facts = get_facts_direct(tc, g, ins->operands[0]);
-                            if (facts->usages == 0) {
+                            if (!MVM_spesh_facts_is_used(tc, g, ins->operands[0])) {
                                 /* Remove this instruction. */
                                 MVM_spesh_manipulate_delete_ins(tc, g, bb, ins);
                                 death = 1;
@@ -2512,7 +2510,7 @@ static void try_eliminate_set(MVMThreadContext *tc, MVMSpeshGraph *g, MVMSpeshBB
             ins->prev->operands[0].reg.orig == ins->operands[1].reg.orig &&
             ins->prev->operands[0].reg.i == ins->operands[1].reg.i) {
         MVMSpeshFacts *elim_facts = get_facts_direct(tc, g, ins->operands[1]);
-        if (elim_facts->usages == 1 && within_inline(tc, g, bb, ins->operands[0])) {
+        if (elim_facts->usages == 1 && !elim_facts->deopt_required && within_inline(tc, g, bb, ins->operands[0])) {
             ins->prev->operands[0].reg = ins->operands[0].reg;
             get_facts_direct(tc, g, ins->prev->operands[0])->writer = ins->prev;
             MVM_spesh_manipulate_delete_ins(tc, g, bb, ins);