diff --git a/arch/um/include/asm/kasan.h b/arch/um/include/asm/kasan.h
index 0d6547f4ec85..f97bb1f7b851 100644
--- a/arch/um/include/asm/kasan.h
+++ b/arch/um/include/asm/kasan.h
@@ -24,7 +24,6 @@
 
 #ifdef CONFIG_KASAN
 void kasan_init(void);
-void kasan_map_memory(void *start, unsigned long len);
 extern int kasan_um_is_ready;
 
 #ifdef CONFIG_STATIC_LINK
diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h
index 81bc38a2e3fc..95521b1f5b20 100644
--- a/arch/um/include/shared/kern_util.h
+++ b/arch/um/include/shared/kern_util.h
@@ -67,4 +67,6 @@ extern void fatal_sigsegv(void) __attribute__ ((noreturn));
 
 void um_idle_sleep(void);
 
+void kasan_map_memory(void *start, size_t len);
+
 #endif
diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 8530b2e08604..c6c9495b1432 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -15,6 +15,7 @@
 #include <sys/vfs.h>
 #include <linux/magic.h>
 #include <init.h>
+#include <kern_util.h>
 #include <os.h>
 
 /*