diff --git a/cmake/image.cmake b/cmake/image.cmake
index 7cfb8fe..8e20c0a 100644
--- a/cmake/image.cmake
+++ b/cmake/image.cmake
@@ -15,6 +15,10 @@ function(nl_add_images target)
             $<TARGET_FILE:${target}> ${out}.bin
     COMMAND ${NL_WM_TOOL} -b ${out}.bin -sb ${SDK_DIR}/Bin/secboot.img -fc compress -it 2M
             -ua 100000 -ra 10100 -df -o ${out}
+    COMMAND ${CMAKE_COMMAND} -DVERSION_HEADER=${CMAKE_BINARY_DIR}/generated/nl_version.h
+            -DMKIMAGE=${CMAKE_SOURCE_DIR}/tools/mkimage/nl_mkimage.py -DIMAGE=${out}_gz.img
+            -DDEVICE=${NINLIGHT_DEVICE} -DOUT=${out}_ota.img
+            -P ${CMAKE_SOURCE_DIR}/cmake/run_mkimage.cmake
     COMMAND ${CMAKE_SIZE} $<TARGET_FILE:${target}>
     COMMENT "Packing ${target}.fls and ${target}_gz.img")
 endfunction()
diff --git a/cmake/run_mkimage.cmake b/cmake/run_mkimage.cmake
new file mode 100644
index 0000000..a0ac4ec
--- /dev/null
+++ b/cmake/run_mkimage.cmake
@@ -0,0 +1,8 @@
+file(READ ${VERSION_HEADER} V)
+string(REGEX MATCH "\"([^\"]*)\"" _m "${V}")
+set(VERSION "${CMAKE_MATCH_1}")
+execute_process(COMMAND python3 ${MKIMAGE} --image ${IMAGE} --device ${DEVICE} --version ${VERSION} --out ${OUT}
+                RESULT_VARIABLE rc)
+if(NOT rc EQUAL 0)
+  message(FATAL_ERROR "nl_mkimage failed (${rc})")
+endif()
diff --git a/tools/build_all.sh b/tools/build_all.sh
index b0a65bf..3879b88 100755
--- a/tools/build_all.sh
+++ b/tools/build_all.sh
@@ -11,3 +11,4 @@ for d in "${DEVICES[@]}"; do
   cmake --build "$OUT/$d"
 done
 ls -1 "$OUT"/*/ninlight_*.fls
+ls -1 "$OUT"/*/ninlight_*_ota.img