diff --git a/src/compiler/iroptimizer.js b/src/compiler/iroptimizer.js
index c161f3c8..15424a72 100644
--- a/src/compiler/iroptimizer.js
+++ b/src/compiler/iroptimizer.js
@@ -17,8 +17,6 @@ class TypeState {
     constructor () {
         /** @type {Object.<string, InputType | 0>}*/
         this.variables = {};
-        /** @type {InputType | 0} */
-        this.defaultType = 0;
     }
 
     /**
@@ -33,7 +31,6 @@ class TypeState {
             }
         }
         this.variables = {};
-        this.defaultType = InputType.ANY;
         return modified;
     }
 
@@ -46,7 +43,6 @@ class TypeState {
         for (const varId in this.variables) {
             clone.variables[varId] = this.variables[varId];
         }
-        clone.defaultType = this.defaultType;
         return clone;
     }
 
@@ -84,8 +80,8 @@ class TypeState {
      */
     or (other) {
         return this.mutate(other, varId => {
-            const thisType = this.variables[varId] ?? this.defaultType;
-            const otherType = other.variables[varId] ?? other.defaultType;
+            const thisType = this.variables[varId] ?? InputType.ANY;
+            const otherType = other.variables[varId] ?? InputType.ANY;
             return thisType | otherType;
         });
     }
@@ -96,9 +92,9 @@ class TypeState {
      */
     after (other) {
         return this.mutate(other, varId => {
-            const otherType = other.variables[varId] ?? other.defaultType;
+            const otherType = other.variables[varId];
             if (otherType !== 0) return otherType;
-            return this.variables[varId] ?? this.defaultType;
+            return this.variables[varId] ?? InputType.ANY;
         });
     }
 
@@ -108,7 +104,7 @@ class TypeState {
      * @returns {boolean}
      */
     setVariableType (variable, type) {
-        if (this.getVariableType(variable) === type) return false;
+        if (this.variables[variable.id] === type) return false;
         this.variables[variable.id] = type;
         return true;
     }
@@ -119,7 +115,7 @@ class TypeState {
      * @returns {InputType}
      */
     getVariableType (variable) {
-        return this.variables[variable.id] ?? (this.defaultType === 0 ? InputType.ANY : this.defaultType);
+        return this.variables[variable.id] ?? InputType.ANY;
     }
 }
 
@@ -528,7 +524,7 @@ class IROptimizer {
             state = state.clone();
         }
 
-        modified = modified || this.analyzeInputs(inputs, state);
+        modified = this.analyzeInputs(inputs, state) || modified;
 
         switch (stackBlock.opcode) {
         case StackOpcode.VAR_SET:
diff --git a/test/fixtures/tw-type-assertions.sb3 b/test/fixtures/tw-type-assertions.sb3
index 406d204a..29392ebe 100644
Binary files a/test/fixtures/tw-type-assertions.sb3 and b/test/fixtures/tw-type-assertions.sb3 differ
diff --git a/test/snapshot/__snapshots__/tw-procedure-return-recursion.sb3.tw-snapshot b/test/snapshot/__snapshots__/tw-procedure-return-recursion.sb3.tw-snapshot
index ee666ba3..b7824ee7 100644
--- a/test/snapshot/__snapshots__/tw-procedure-return-recursion.sb3.tw-snapshot
+++ b/test/snapshot/__snapshots__/tw-procedure-return-recursion.sb3.tw-snapshot
@@ -10,17 +10,17 @@ return function* genXYZ () {
 yield* executeInCompatibilityLayer({"MESSAGE":"plan 18",}, b0, false, false, "G", null);
 b1.value = 0;
 b2.value = (yield* thread.procedures["Znon warp recursion should yield %s"](8));
-if ((b1.value === 4)) {
+if (((+b1.value || 0) === 4)) {
 yield* executeInCompatibilityLayer({"MESSAGE":"pass non warp recursion yields",}, b0, false, false, "ao", null);
 }
 b1.value = 0;
 b2.value = thread.procedures["Wwarp recursion should not yield %s"](8);
-if ((b1.value === 0)) {
+if (compareEqual(b1.value, 0)) {
 yield* executeInCompatibilityLayer({"MESSAGE":"pass warp recursion does not yield",}, b0, false, false, "ar", null);
 }
 b1.value = 0;
 b2.value = (yield* thread.procedures["Zfib %s"](7));
-if ((b1.value === 20)) {
+if (((+b1.value || 0) === 20)) {
 yield* executeInCompatibilityLayer({"MESSAGE":"pass non warp fib yielded",}, b0, false, false, "au", null);
 }
 yield* thread.procedures["Zrecursing yields between each %s"]("initial");
@@ -68,7 +68,7 @@ return function* genXYZ_recursing_yields_bet (p0) {
 if ((("" + p0).toLowerCase() === "initial".toLowerCase())) {
 b0.value = 0;
 b1.value = ((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 1)) || 0) + (((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 1)) || 0) + (((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 2)) || 0) + (((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 2)) || 0) + (((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 3)) || 0) + (+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 3)) || 0)) || 0)) || 0)) || 0)) || 0));
-if ((b0.value === 3)) {
+if (((+b0.value || 0) === 3)) {
 yield* executeInCompatibilityLayer({"MESSAGE":"pass recursing between calls yields final",}, b2, false, false, "aK", null);
 } else {
 yield* executeInCompatibilityLayer({"MESSAGE":"fail recursing between calls yields final",}, b2, false, false, "aL", null);
diff --git a/test/snapshot/__snapshots__/warp-timer/tw-procedure-return-recursion.sb3.tw-snapshot b/test/snapshot/__snapshots__/warp-timer/tw-procedure-return-recursion.sb3.tw-snapshot
index ee666ba3..b7824ee7 100644
--- a/test/snapshot/__snapshots__/warp-timer/tw-procedure-return-recursion.sb3.tw-snapshot
+++ b/test/snapshot/__snapshots__/warp-timer/tw-procedure-return-recursion.sb3.tw-snapshot
@@ -10,17 +10,17 @@ return function* genXYZ () {
 yield* executeInCompatibilityLayer({"MESSAGE":"plan 18",}, b0, false, false, "G", null);
 b1.value = 0;
 b2.value = (yield* thread.procedures["Znon warp recursion should yield %s"](8));
-if ((b1.value === 4)) {
+if (((+b1.value || 0) === 4)) {
 yield* executeInCompatibilityLayer({"MESSAGE":"pass non warp recursion yields",}, b0, false, false, "ao", null);
 }
 b1.value = 0;
 b2.value = thread.procedures["Wwarp recursion should not yield %s"](8);
-if ((b1.value === 0)) {
+if (compareEqual(b1.value, 0)) {
 yield* executeInCompatibilityLayer({"MESSAGE":"pass warp recursion does not yield",}, b0, false, false, "ar", null);
 }
 b1.value = 0;
 b2.value = (yield* thread.procedures["Zfib %s"](7));
-if ((b1.value === 20)) {
+if (((+b1.value || 0) === 20)) {
 yield* executeInCompatibilityLayer({"MESSAGE":"pass non warp fib yielded",}, b0, false, false, "au", null);
 }
 yield* thread.procedures["Zrecursing yields between each %s"]("initial");
@@ -68,7 +68,7 @@ return function* genXYZ_recursing_yields_bet (p0) {
 if ((("" + p0).toLowerCase() === "initial".toLowerCase())) {
 b0.value = 0;
 b1.value = ((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 1)) || 0) + (((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 1)) || 0) + (((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 2)) || 0) + (((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 2)) || 0) + (((+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 3)) || 0) + (+(yield* yieldThenCallGenerator(thread.procedures["Zrecursing yields between each %s"], 3)) || 0)) || 0)) || 0)) || 0)) || 0));
-if ((b0.value === 3)) {
+if (((+b0.value || 0) === 3)) {
 yield* executeInCompatibilityLayer({"MESSAGE":"pass recursing between calls yields final",}, b2, false, false, "aK", null);
 } else {
 yield* executeInCompatibilityLayer({"MESSAGE":"fail recursing between calls yields final",}, b2, false, false, "aL", null);