diff --git a/src/qlever-petrimaps/Misc.h b/src/qlever-petrimaps/Misc.h
index 9f66175..3782280 100644
--- a/src/qlever-petrimaps/Misc.h
+++ b/src/qlever-petrimaps/Misc.h
@@ -15,7 +15,7 @@
 #ifndef PETRIMAPS_MISC_H_
 #define PETRIMAPS_MISC_H_
 
-#define ID_TYPE size_t
+#define ID_TYPE uint32_t
 #define QLEVER_ID_TYPE size_t
 
 const static ID_TYPE I_OFFSET = 500000000;