diff --git a/support/scripts/check-dotconfig.py b/support/scripts/check-dotconfig.py
new file mode 100755
index 0000000000..f9a416b743
--- /dev/null
+++ b/support/scripts/check-dotconfig.py
@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+
+# This scripts check that all lines present in the defconfig are
+# still present in the .config
+
+import sys
+
+
+def main():
+    if not (len(sys.argv) == 3):
+        print("Error: incorrect number of arguments")
+        print("""Usage: check-dotconfig <configfile> <defconfig>""")
+        sys.exit(1)
+
+    configfile = sys.argv[1]
+    defconfig = sys.argv[2]
+
+    # strip() to get rid of trailing \n
+    with open(configfile) as configf:
+        configlines = [l.strip() for l in configf.readlines()]
+
+    defconfiglines = []
+    with open(defconfig) as defconfigf:
+        # strip() to get rid of trailing \n
+        for line in (line.strip() for line in defconfigf.readlines()):
+            if line.startswith("BR2_"):
+                defconfiglines.append(line)
+            elif line.startswith('# BR2_') and line.endswith(' is not set'):
+                defconfiglines.append(line)
+
+    # Check that all the defconfig lines are still present
+    missing = [line for line in defconfiglines if line not in configlines]
+
+    if missing:
+        print("WARN: defconfig {} can't be used:".format(defconfig))
+        for m in missing:
+            print("      Missing: {}".format(m))
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()