diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
index 49869687a..39e245f22 100644
--- a/baselines/dom.generated.d.ts
+++ b/baselines/dom.generated.d.ts
@@ -1386,7 +1386,7 @@ interface Keyframe {
     composite?: CompositeOperationOrAuto;
     easing?: string;
     offset?: number | null;
-    [property: string]: string | number | null | undefined;
+    [property: string]: string | number | CSSStyleValue | null | undefined;
 }
 
 interface KeyframeAnimationOptions extends KeyframeEffectOptions {
@@ -2006,7 +2006,7 @@ interface PropertyIndexedKeyframes {
     composite?: CompositeOperationOrAuto | CompositeOperationOrAuto[];
     easing?: string | string[];
     offset?: number | (number | null)[];
-    [property: string]: string | string[] | number | null | (number | null)[] | undefined;
+    [property: string]: string | string[] | number | CSSStyleValue | CSSStyleValue[] | null | (number | null)[] | undefined;
 }
 
 interface PublicKeyCredentialCreationOptions {
diff --git a/baselines/ts5.5/dom.generated.d.ts b/baselines/ts5.5/dom.generated.d.ts
index c2605d732..b7fe41292 100644
--- a/baselines/ts5.5/dom.generated.d.ts
+++ b/baselines/ts5.5/dom.generated.d.ts
@@ -1383,7 +1383,7 @@ interface Keyframe {
     composite?: CompositeOperationOrAuto;
     easing?: string;
     offset?: number | null;
-    [property: string]: string | number | null | undefined;
+    [property: string]: string | number | CSSStyleValue | null | undefined;
 }
 
 interface KeyframeAnimationOptions extends KeyframeEffectOptions {
@@ -2003,7 +2003,7 @@ interface PropertyIndexedKeyframes {
     composite?: CompositeOperationOrAuto | CompositeOperationOrAuto[];
     easing?: string | string[];
     offset?: number | (number | null)[];
-    [property: string]: string | string[] | number | null | (number | null)[] | undefined;
+    [property: string]: string | string[] | number | CSSStyleValue | CSSStyleValue[] | null | (number | null)[] | undefined;
 }
 
 interface PublicKeyCredentialCreationOptions {
diff --git a/baselines/ts5.6/dom.generated.d.ts b/baselines/ts5.6/dom.generated.d.ts
index 080755c34..3ad1bd245 100644
--- a/baselines/ts5.6/dom.generated.d.ts
+++ b/baselines/ts5.6/dom.generated.d.ts
@@ -1383,7 +1383,7 @@ interface Keyframe {
     composite?: CompositeOperationOrAuto;
     easing?: string;
     offset?: number | null;
-    [property: string]: string | number | null | undefined;
+    [property: string]: string | number | CSSStyleValue | null | undefined;
 }
 
 interface KeyframeAnimationOptions extends KeyframeEffectOptions {
@@ -2003,7 +2003,7 @@ interface PropertyIndexedKeyframes {
     composite?: CompositeOperationOrAuto | CompositeOperationOrAuto[];
     easing?: string | string[];
     offset?: number | (number | null)[];
-    [property: string]: string | string[] | number | null | (number | null)[] | undefined;
+    [property: string]: string | string[] | number | CSSStyleValue | CSSStyleValue[] | null | (number | null)[] | undefined;
 }
 
 interface PublicKeyCredentialCreationOptions {
diff --git a/baselines/ts5.9/dom.generated.d.ts b/baselines/ts5.9/dom.generated.d.ts
index e7d397376..6acad99c9 100644
--- a/baselines/ts5.9/dom.generated.d.ts
+++ b/baselines/ts5.9/dom.generated.d.ts
@@ -1383,7 +1383,7 @@ interface Keyframe {
     composite?: CompositeOperationOrAuto;
     easing?: string;
     offset?: number | null;
-    [property: string]: string | number | null | undefined;
+    [property: string]: string | number | CSSStyleValue | null | undefined;
 }
 
 interface KeyframeAnimationOptions extends KeyframeEffectOptions {
@@ -2003,7 +2003,7 @@ interface PropertyIndexedKeyframes {
     composite?: CompositeOperationOrAuto | CompositeOperationOrAuto[];
     easing?: string | string[];
     offset?: number | (number | null)[];
-    [property: string]: string | string[] | number | null | (number | null)[] | undefined;
+    [property: string]: string | string[] | number | CSSStyleValue | CSSStyleValue[] | null | (number | null)[] | undefined;
 }
 
 interface PublicKeyCredentialCreationOptions {
diff --git a/inputfiles/overridingTypes.jsonc b/inputfiles/overridingTypes.jsonc
index c6e2832d5..bd04272a8 100644
--- a/inputfiles/overridingTypes.jsonc
+++ b/inputfiles/overridingTypes.jsonc
@@ -2923,13 +2923,13 @@
             "BaseKeyframe": {
                 "name": "Keyframe",
                 "overrideIndexSignatures": [
-                    "[property: string]: string | number | null | undefined"
+                    "[property: string]: string | number | CSSStyleValue | null | undefined"
                 ]
             },
             "BasePropertyIndexedKeyframe": {
                 "name": "PropertyIndexedKeyframes",
                 "overrideIndexSignatures": [
-                    "[property: string]: string | string[] | number | null | (number | null)[] | undefined"
+                    "[property: string]: string | string[] | number | CSSStyleValue | CSSStyleValue[] | null | (number | null)[] | undefined"
                 ]
             },
             "BaseComputedKeyframe": {