diff --git a/services/healthreport/healthreporter.jsm b/services/healthreport/healthreporter.jsm
index 2104f2e0ad7a..482d08f4e487 100644
--- a/services/healthreport/healthreporter.jsm
+++ b/services/healthreport/healthreporter.jsm
@@ -307,6 +307,9 @@ HealthReporter.prototype = Object.freeze({
     this._log.info("HealthReporter started.");
     this._initialized = true;
     Services.obs.addObserver(this, "idle-daily", false);
+
+    // Clean up caches and reduce memory usage.
+    this._storage.compact();
     this._initializedDeferred.resolve(this);
   },
 
@@ -695,6 +698,7 @@ HealthReporter.prototype = Object.freeze({
       o.errors = errors;
     }
 
+    this._storage.compact();
     throw new Task.Result(JSON.stringify(o));
   },
 
diff --git a/services/metrics/storage.jsm b/services/metrics/storage.jsm
index 1f590b229966..7dd432fa4a44 100644
--- a/services/metrics/storage.jsm
+++ b/services/metrics/storage.jsm
@@ -1204,6 +1204,21 @@ MetricsStorageSqliteBackend.prototype = Object.freeze({
     });
   },
 
+  /**
+   * Reduce memory usage as much as possible.
+   *
+   * This returns a promise that will be resolved on completion.
+   *
+   * @return Promise<>
+   */
+  compact: function () {
+    let self = this;
+    return this.enqueueOperation(function doCompact() {
+      self._connection.discardCachedStatements();
+      return self._connection.shrinkMemory();
+    });
+  },
+
   /**
    * Ensure a field ID matches a specified type.
    *