diff --git a/gum/backend-arm/gumstalker-arm.c b/gum/backend-arm/gumstalker-arm.c
index c4fb2ed65..1519a3677 100644
--- a/gum/backend-arm/gumstalker-arm.c
+++ b/gum/backend-arm/gumstalker-arm.c
@@ -1599,8 +1599,7 @@ _gum_stalker_modify_to_run_on_thread (GumStalker * self,
   GumExecCtx * ctx;
   guint32 pc;
   GumArmWriter * cw;
-  GumAddress cpu_context_copy;
-  guint32 infect_body;
+  GumAddress cpu_context_copy, infect_body;
 
   ctx = gum_stalker_create_exec_ctx (self, thread_id, NULL, NULL);
   if ((cpu_context->cpsr & GUM_PSR_T_BIT) == 0)
@@ -1617,7 +1616,7 @@ _gum_stalker_modify_to_run_on_thread (GumStalker * self,
   cpu_context_copy = GUM_ADDRESS (gum_arm_writer_cur (cw));
   gum_arm_writer_put_bytes (cw, (guint8 *) cpu_context, sizeof (GumCpuContext));
 
-  infect_body = GPOINTER_TO_SIZE (gum_arm_writer_cur (cw));
+  infect_body = GUM_ADDRESS (gum_arm_writer_cur (cw));
 
   gum_exec_ctx_write_arm_prolog (ctx, cw);