diff --git a/arch/x86/um/os-Linux/task_size.c b/arch/x86/um/os-Linux/task_size.c
index 8502ad30e61bcfc49a9e28c975d356b4b628a62c..5adb6a2fd117df01c232156e2091bfc3d190eac7 100644
--- a/arch/x86/um/os-Linux/task_size.c
+++ b/arch/x86/um/os-Linux/task_size.c
@@ -109,7 +109,7 @@ unsigned long os_get_top_address(void)
 		exit(1);
 	}
 
-	printf("0x%x\n", bottom << UM_KERN_PAGE_SHIFT);
+	printf("0x%lx\n", bottom << UM_KERN_PAGE_SHIFT);
 	printf("Locating the top of the address space ... ");
 	fflush(stdout);
 
@@ -134,7 +134,7 @@ unsigned long os_get_top_address(void)
 		exit(1);
 	}
 	top <<= UM_KERN_PAGE_SHIFT;
-	printf("0x%x\n", top);
+	printf("0x%lx\n", top);
 
 	return top;
 }