diff --git a/apps/btadv/app.ts b/apps/btadv/app.ts
index c66ba3449..85fd3a5d3 100644
--- a/apps/btadv/app.ts
+++ b/apps/btadv/app.ts
@@ -686,7 +686,7 @@ const setIntervals = (
 const redrawInterval = setInterval(redraw, /*replaced*/1000);
 Bangle.on("lock", locked => setIntervals(locked));
 
-let bleInterval: undefined | number;
+let bleInterval: undefined | IntervalId;
 NRF.on("connect", () => setIntervals(undefined, true));
 NRF.on("disconnect", () => setIntervals(undefined, false));
 
diff --git a/apps/clkinfostopw/clkinfo.ts b/apps/clkinfostopw/clkinfo.ts
index 5a2fd7bd0..f0c2a6ccb 100644
--- a/apps/clkinfostopw/clkinfo.ts
+++ b/apps/clkinfostopw/clkinfo.ts
@@ -1,6 +1,6 @@
 (() => {
   let durationOnPause = "---";
-  let redrawInterval: number | undefined;
+  let redrawInterval: IntervalId | undefined;
   let startTime: number | undefined;
   let showMillis = true;
   const milliTime = 60;
@@ -16,7 +16,7 @@
         if (startTime) {
             if (showMillis && Date.now() - startTime > milliTime * 1000) {
                 showMillis = false;
-                changeInterval(redrawInterval, 1000);
+                changeInterval(redrawInterval!, 1000);
             }
         } else {
             unqueueRedraw();
diff --git a/apps/drained/app.ts b/apps/drained/app.ts
index 3adfbec02..f4d33bc44 100644
--- a/apps/drained/app.ts
+++ b/apps/drained/app.ts
@@ -1,7 +1,7 @@
 const app = "drained";
 
 // from boot.js
-declare var drainedInterval: number | undefined;
+declare var drainedInterval: IntervalId | undefined;
 if(typeof drainedInterval !== "undefined")
   drainedInterval = clearInterval(drainedInterval) as undefined;
 
@@ -41,7 +41,7 @@ Bangle.setOptions({
 });
 
 // clock
-let nextDraw: number | undefined;
+let nextDraw: TimeoutId | undefined;
 const draw = () => {
   const x = g.getWidth() / 2;
   const y = g.getHeight() / 2 - 48;
diff --git a/apps/widhid/wid.ts b/apps/widhid/wid.ts
index e788be1a8..c8bd2410f 100644
--- a/apps/widhid/wid.ts
+++ b/apps/widhid/wid.ts
@@ -10,7 +10,7 @@
 	let anchor = {x:0,y:0};
 	let start = {x:0,y:0};
 	let dragging = false;
-	let activeTimeout: number | undefined;
+	let activeTimeout: TimeoutId | undefined;
 	let waitForRelease = true;
 
 	const onSwipe = ((_lr, ud) => {