diff --git a/src/ai/ai-moveset-gen.ts b/src/ai/ai-moveset-gen.ts
index 043c93451cf..f392ca46d3f 100644
--- a/src/ai/ai-moveset-gen.ts
+++ b/src/ai/ai-moveset-gen.ts
@@ -133,6 +133,8 @@ function getTmPoolForSpecies(
 ): void {
   const [allowCommon, allowGreat, allowUltra] = allowedTiers;
   const tms = speciesTmMoves[speciesId];
+  // Species with no learnable TMs (e.g. Ditto) don't have entries in the `speciesTmMoves` object,
+  // so this is needed to avoid iterating over `undefined`
   if (tms == null) {
     return;
   }
diff --git a/test/ai/ai-moveset-gen.test.ts b/test/ai/ai-moveset-gen.test.ts
index 86ca929be77..6d927926131 100644
--- a/test/ai/ai-moveset-gen.test.ts
+++ b/test/ai/ai-moveset-gen.test.ts
@@ -41,6 +41,8 @@ interface MockPokemonParams {
 /**
  * Construct an `EnemyPokemon` that can be used for testing
  * @param species - The species ID of the pokemon to create
+ * @returns The newly created `EnemyPokemon`.
+ * @todo Move this to a dedicated unit test util folder if more tests come to rely on it
  */
 function createTestablePokemon(
   species: SpeciesId,
@@ -269,7 +271,7 @@ describe("Regression Tests - ai-moveset-gen.ts", () => {
   describe("getTmPoolForSpecies", () => {
     const { getTmPoolForSpecies } = __INTERNAL_TEST_EXPORTS;
 
-    it("should not crash when generating a moveset for Ditto", () => {
+    it("should not crash when generating a moveset for Pokemon without TM moves", () => {
       pokemon = createTestablePokemon(SpeciesId.DITTO, { level: 50 });
       expect(() =>
         getTmPoolForSpecies(SpeciesId.DITTO, ULTRA_TIER_TM_LEVEL_REQUIREMENT, "", new Map(), new Map(), new Map(), [