diff --git a/src/aw-client.ts b/src/aw-client.ts
index 23e29e6..eefa344 100644
--- a/src/aw-client.ts
+++ b/src/aw-client.ts
@@ -343,31 +343,50 @@ export class AWClient {
 
             // If all results were cached, return them
             if (cacheResults.every((r) => r !== null)) {
+                //console.debug("Returning fully cached query results");
                 return cacheResults;
             }
-
-            // Otherwise, query with remaining timeperiods
-            data.timeperiods = data.timeperiods.filter(
-                (_, i) => cacheResults[i] === null,
-            );
         }
 
-        const queryResults = await this._post("/0/query/", data);
+        const timeperiodsNotCached = data.timeperiods.filter(
+            (_, i) => cacheResults[i] === null,
+        );
+
+        // Otherwise, query with remaining timeperiods
+        const queryResults = await this._post("/0/query/", {
+            ...data,
+            timeperiods: timeperiodsNotCached,
+        });
 
         if (params.cache) {
+            /*
+            if (cacheResults.every((r) => r === null)) {
+                console.debug("Returning uncached query results");
+            } else if (
+                cacheResults.some((r) => r === null) &&
+                cacheResults.some((r) => r !== null)
+            ) {
+                console.debug("Returning partially cached query results");
+            }
+            */
+
             // Cache results
             for (const [i, result] of queryResults.entries()) {
                 const cacheKey = JSON.stringify({
-                    timeperiod: data.timeperiods[i],
+                    timeperiod: timeperiodsNotCached[i],
                     query,
                 });
                 this.queryCache[cacheKey] = result;
             }
 
-            // Return all results
-            return cacheResults.map(
-                (r: any, i: number) => r ?? queryResults[i],
-            );
+            // Return all results from cache
+            return timeperiods.map((_, i) => {
+                const cacheKey = JSON.stringify({
+                    timeperiod: data.timeperiods[i],
+                    query,
+                });
+                return this.queryCache[cacheKey];
+            });
         } else {
             return queryResults;
         }
diff --git a/src/test/test.ts b/src/test/test.ts
index fa0b2cd..f640d9c 100644
--- a/src/test/test.ts
+++ b/src/test/test.ts
@@ -155,10 +155,15 @@ describe("Basic API usage", () => {
     });
 
     it("Query", async () => {
-        const e1 = { ...testevent, timestamp: new Date("2022-01-01") };
-        const e2 = { ...testevent, timestamp: new Date("2022-01-02") };
+        const d1 = new Date("2022-01-01");
+        const d2 = new Date("2022-01-02");
+        const d3 = new Date("2022-01-03");
+        const e1 = { ...testevent, timestamp: d1 };
+        const e2 = { ...testevent, timestamp: d2 };
+        const e3 = { ...testevent, timestamp: d3 };
         await awc.heartbeat(bucketId, 5, e1);
         await awc.heartbeat(bucketId, 5, e2);
+        await awc.heartbeat(bucketId, 5, e3);
 
         // Both these are valid timeperiod specs
         const timeperiods = [
@@ -178,7 +183,20 @@ describe("Basic API usage", () => {
             e2.timestamp.toISOString(),
             new Date(resp_e1.timestamp).toISOString(),
         );
-        assert.equal(e2.data.label, resp[0][0].data.label);
+        assert.equal(e2.data.label, resp_e1.data.label);
+
+        // Run query again and check that the results are the same (correctly cached)
+        const resp2: IEvent[][] = await awc.query(timeperiods, query);
+        assert.deepEqual(resp, resp2);
+
+        // Add a timeperiod and query again, to check that partial cache works
+        const timeperiods2 = [
+            { start: d1, end: d2 },
+            { start: d2, end: d3 },
+        ];
+        const resp3: IEvent[][] = await awc.query(timeperiods2, query);
+        assert.equal(2, resp3[0].length);
+        assert.equal(2, resp3[1].length);
     });
 });