diff --git a/spec/integ/sliding-sync-sdk.spec.ts b/spec/integ/sliding-sync-sdk.spec.ts
index 50fe0652e..37fcd879f 100644
--- a/spec/integ/sliding-sync-sdk.spec.ts
+++ b/spec/integ/sliding-sync-sdk.spec.ts
@@ -671,32 +671,17 @@ describe("SlidingSyncSdk", () => {
             // TODO: more assertions?
         });
 
-        it("can update OTK counts", () => {
-            client!.crypto!.updateOneTimeKeyCount = jest.fn();
+        it("can update OTK counts and unused fallback keys", () => {
+            client!.crypto!.processKeyCounts = jest.fn();
             ext.onResponse({
                 device_one_time_keys_count: {
                     signed_curve25519: 42,
                 },
-            });
-            expect(client!.crypto!.updateOneTimeKeyCount).toHaveBeenCalledWith(42);
-            ext.onResponse({
-                device_one_time_keys_count: {
-                    not_signed_curve25519: 42,
-                    // missing field -> default to 0
-                },
-            });
-            expect(client!.crypto!.updateOneTimeKeyCount).toHaveBeenCalledWith(0);
-        });
-
-        it("can update fallback keys", () => {
-            ext.onResponse({
                 device_unused_fallback_key_types: ["signed_curve25519"],
             });
-            expect(client!.crypto!.getNeedsNewFallback()).toEqual(false);
-            ext.onResponse({
-                device_unused_fallback_key_types: ["not_signed_curve25519"],
-            });
-            expect(client!.crypto!.getNeedsNewFallback()).toEqual(true);
+            expect(client!.crypto!.processKeyCounts).toHaveBeenCalledWith({ signed_curve25519: 42 }, [
+                "signed_curve25519",
+            ]);
         });
     });
 
diff --git a/src/crypto/index.ts b/src/crypto/index.ts
index 4c10b1c16..3c787a0c2 100644
--- a/src/crypto/index.ts
+++ b/src/crypto/index.ts
@@ -1817,31 +1817,6 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
         });
     }
 
-    /**
-     * Stores the current one_time_key count which will be handled later (in a call of
-     * onSyncCompleted). The count is e.g. coming from a /sync response.
-     *
-     * @param currentCount - The current count of one_time_keys to be stored
-     *
-     * TODO This method is called in `processKeyCounts` method and in the `sliding-sync-sdk`.
-     * TODO The `sliding-sync-sdk` should call `processKeyCounts` directly instead of `updateOneTimeKeyCount`
-     * TODO Move the content of `updateOneTimeKeyCount` in `processKeyCounts` after the `sliding-sync-sdk` change
-     */
-    public updateOneTimeKeyCount(currentCount: number): void {
-        if (isFinite(currentCount)) {
-            this.oneTimeKeyCount = currentCount;
-        } else {
-            throw new TypeError("Parameter for updateOneTimeKeyCount has to be a number");
-        }
-    }
-
-    // TODO This method is called in `processKeyCounts`, `uploadOneTimeKeys` methods and in the `sliding-sync-sdk`.
-    // TODO The `sliding-sync-sdk` should call `processKeyCounts` directly instead of `setNeedsNewFallback`
-    // TODO Move the content of `setNeedsNewFallback` in `processKeyCounts` after the `sliding-sync-sdk` change
-    public setNeedsNewFallback(needsNewFallback: boolean): void {
-        this.needsNewFallback = needsNewFallback;
-    }
-
     public getNeedsNewFallback(): boolean {
         return !!this.needsNewFallback;
     }
@@ -1977,7 +1952,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
                 fallbackJson["signed_curve25519:" + keyId] = k;
                 promises.push(this.signObject(k));
             }
-            this.setNeedsNewFallback(false);
+            this.needsNewFallback = false;
         }
 
         const oneTimeKeys = await this.olmDevice.getOneTimeKeys();
@@ -3222,6 +3197,20 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
         });
     }
 
+    /**
+     * Stores the current one_time_key count which will be handled later (in a call of
+     * onSyncCompleted).
+     *
+     * @param currentCount - The current count of one_time_keys to be stored
+     */
+    private updateOneTimeKeyCount(currentCount: number): void {
+        if (isFinite(currentCount)) {
+            this.oneTimeKeyCount = currentCount;
+        } else {
+            throw new TypeError("Parameter for updateOneTimeKeyCount has to be a number");
+        }
+    }
+
     public processKeyCounts(oneTimeKeysCounts?: Record<string, number>, unusedFallbackKeys?: string[]): Promise<void> {
         if (oneTimeKeysCounts !== undefined) {
             this.updateOneTimeKeyCount(oneTimeKeysCounts["signed_curve25519"] || 0);
@@ -3232,7 +3221,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
             // is present in the sync response, which indicates that the server supports fallback keys.
             //
             // If there's no unused signed_curve25519 fallback key, we need a new one.
-            this.setNeedsNewFallback(!unusedFallbackKeys.includes("signed_curve25519"));
+            this.needsNewFallback = !unusedFallbackKeys.includes("signed_curve25519");
         }
 
         return Promise.resolve();
diff --git a/src/sliding-sync-sdk.ts b/src/sliding-sync-sdk.ts
index 93e29e0ba..de2365f38 100644
--- a/src/sliding-sync-sdk.ts
+++ b/src/sliding-sync-sdk.ts
@@ -94,21 +94,12 @@ class ExtensionE2EE implements Extension<ExtensionE2EERequest, ExtensionE2EEResp
             );
         }
 
-        // Handle one_time_keys_count
-        if (data["device_one_time_keys_count"]) {
-            const currentCount = data["device_one_time_keys_count"].signed_curve25519 || 0;
-            this.crypto.updateOneTimeKeyCount(currentCount);
-        }
-        if (data["device_unused_fallback_key_types"] || data["org.matrix.msc2732.device_unused_fallback_key_types"]) {
-            // The presence of device_unused_fallback_key_types indicates that the
-            // server supports fallback keys. If there's no unused
-            // signed_curve25519 fallback key we need a new one.
-            const unusedFallbackKeys =
-                data["device_unused_fallback_key_types"] || data["org.matrix.msc2732.device_unused_fallback_key_types"];
-            this.crypto.setNeedsNewFallback(
-                Array.isArray(unusedFallbackKeys) && !unusedFallbackKeys.includes("signed_curve25519"),
-            );
-        }
+        // Handle one_time_keys_count and unused_fallback_key_types
+        await this.crypto.processKeyCounts(
+            data.device_one_time_keys_count,
+            data["device_unused_fallback_key_types"] || data["org.matrix.msc2732.device_unused_fallback_key_types"],
+        );
+
         this.crypto.onSyncCompleted({});
     }
 }