diff --git a/src/Core/DataFilter.l b/src/Core/DataFilter.l
index d599015f8..b4c0d21cf 100644
--- a/src/Core/DataFilter.l
+++ b/src/Core/DataFilter.l
@@ -1,3 +1,7 @@
+%top{
+  #include <stdint.h>
+}
+
 %{
 /*
  * Copyright (c) 2010 Mark Liversedge (liversedge@gmail.com)
diff --git a/src/Core/RideDB.l b/src/Core/RideDB.l
index a0e4e3592..2208921d9 100644
--- a/src/Core/RideDB.l
+++ b/src/Core/RideDB.l
@@ -1,3 +1,7 @@
+%top{
+  #include <stdint.h>
+}
+
 %{
 /*
  * Copyright (c) 2010 Mark Liversedge (liversedge@gmail.com)
diff --git a/src/FileIO/JsonRideFile.l b/src/FileIO/JsonRideFile.l
index 9cf5cfc78..ef431095f 100644
--- a/src/FileIO/JsonRideFile.l
+++ b/src/FileIO/JsonRideFile.l
@@ -1,3 +1,7 @@
+%top{
+  #include <stdint.h>
+}
+
 %{
 /*
  * Copyright (c) 2010 Mark Liversedge (liversedge@gmail.com)
diff --git a/src/Train/TrainerDayAPIQuery.l b/src/Train/TrainerDayAPIQuery.l
index 05e8eeeb7..ed5f71e4f 100644
--- a/src/Train/TrainerDayAPIQuery.l
+++ b/src/Train/TrainerDayAPIQuery.l
@@ -1,3 +1,7 @@
+%top{
+  #include <stdint.h>
+}
+
 %{
 /*
  * Copyright (c) 2024 Joachim Kohlhammer (joachim.kohlhammer@gmx.de)
diff --git a/src/Train/WorkoutFilter.l b/src/Train/WorkoutFilter.l
index 6ac7c9693..1b861a441 100644
--- a/src/Train/WorkoutFilter.l
+++ b/src/Train/WorkoutFilter.l
@@ -1,3 +1,7 @@
+%top{
+  #include <stdint.h>
+}
+
 %{
 /*
  * Copyright (c) 2023 Joachim Kohlhammer (joachim.kohlhammer@gmx.de)