diff --git a/include/image.mk b/include/image.mk
index 6e0456f42ac..31689c7e6b8 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -244,8 +244,8 @@ endef
 
 define Image/mkfs/prepare/default
 	# Use symbolic permissions to avoid clobbering SUID/SGID/sticky bits
-	- $(FIND) $(TARGET_DIR) -type f -not -perm +0100 -not -name 'ssh_host*' -not -name 'shadow' -print0 | $(XARGS) -0 chmod u+rw,g+r,o+r
-	- $(FIND) $(TARGET_DIR) -type f -perm +0100 -print0 | $(XARGS) -0 chmod u+rwx,g+rx,o+rx
+	- $(FIND) $(TARGET_DIR) -type f -not -perm /0100 -not -name 'ssh_host*' -not -name 'shadow' -print0 | $(XARGS) -0 chmod u+rw,g+r,o+r
+	- $(FIND) $(TARGET_DIR) -type f -perm /0100 -print0 | $(XARGS) -0 chmod u+rwx,g+rx,o+rx
 	- $(FIND) $(TARGET_DIR) -type d -print0 | $(XARGS) -0 chmod u+rwx,g+rx,o+rx
 	$(INSTALL_DIR) $(TARGET_DIR)/tmp $(TARGET_DIR)/overlay
 	chmod 1777 $(TARGET_DIR)/tmp