diff --git a/meta-arm/recipes-bsp/trusted-firmware-a/cot-dt2c_0.1.0.bb b/meta-arm/recipes-bsp/trusted-firmware-a/cot-dt2c_0.1.0.bb
index 7d9dec48..8d8ddf06 100644
--- a/meta-arm/recipes-bsp/trusted-firmware-a/cot-dt2c_0.1.0.bb
+++ b/meta-arm/recipes-bsp/trusted-firmware-a/cot-dt2c_0.1.0.bb
@@ -12,6 +12,10 @@ LIC_FILES_CHKSUM = "file://docs/license.rst;md5=6ed7bace7b0bc63021c6eba7b524039e
 SRCREV = "da738d5eae93af342fdc4995dd3c05acb4c9d757"
 SRCBRANCH = "master"
 
+# The tools use the TF-A source when performing a version check, not
+# the version of this within the source.  So, disable checking
+UPSTREAM_VERSION_UNKNOWN = "1"
+
 inherit python_poetry_core
 
 BBCLASSEXTEND = "native nativesdk"