diff --git a/package/mksh/mksh.mk b/package/mksh/mksh.mk
index b5706dbe0f..4fa0e020af 100644
--- a/package/mksh/mksh.mk
+++ b/package/mksh/mksh.mk
@@ -21,4 +21,12 @@ define MKSH_INSTALL_TARGET_CMDS
 	$(INSTALL) -m 0755 -D $(@D)/mksh $(TARGET_DIR)/bin/mksh
 endef
 
+# Add /bin/mksh to /etc/shells otherwise some login tools like dropbear
+# can reject the user connection. See man shells.
+define MKSH_ADD_MKSH_TO_SHELLS
+	grep -qsE '^/bin/mksh$$' $(TARGET_DIR)/etc/shells \
+		|| echo "/bin/mksh" >> $(TARGET_DIR)/etc/shells
+endef
+MKSH_TARGET_FINALIZE_HOOKS += MKSH_ADD_MKSH_TO_SHELLS
+
 $(eval $(generic-package))