diff --git a/meta-digi-dey/classes/trustfence.bbclass b/meta-digi-dey/classes/trustfence.bbclass
index 3ee0affed..d86f3dcfc 100644
--- a/meta-digi-dey/classes/trustfence.bbclass
+++ b/meta-digi-dey/classes/trustfence.bbclass
@@ -35,7 +35,6 @@ python () {
     import binascii
     import hashlib
     import os
-    import glob
 
     # Secure console configuration
     if (d.getVar("TRUSTFENCE_CONSOLE_DISABLE", True) == "1"):
@@ -80,8 +79,8 @@ python () {
             key_index = int(d.getVar("TRUSTFENCE_KEY_INDEX", True))
         key_index_1 = key_index + 1
 
-        # Set the private key.
-        d.setVar("SWUPDATE_PRIVATE_KEY", glob.glob(keys_path + "/keys/IMG" + str(key_index_1) + "*key.pem")[0])
+        # Set the private key template, it will be expanded later in 'swu' recipes once keys are generated.
+        d.setVar("SWUPDATE_PRIVATE_KEY_TEMPLATE", keys_path + "/keys/IMG" + str(key_index_1) + "*key.pem")
 
         # Set the key password.
         d.setVar("SWUPDATE_PASSWORD_FILE", keys_path + "/keys/key_pass.txt")
diff --git a/meta-digi-dey/recipes-digi/swu-images/core-image-base-swu.bb b/meta-digi-dey/recipes-digi/swu-images/core-image-base-swu.bb
index 5dd78ecbb..bd81b2b07 100644
--- a/meta-digi-dey/recipes-digi/swu-images/core-image-base-swu.bb
+++ b/meta-digi-dey/recipes-digi/swu-images/core-image-base-swu.bb
@@ -38,6 +38,13 @@ python () {
     d.setVarFlag("SWUPDATE_IMAGES_FSTYPES", "core-image-base", img_fstypes)
 }
 
+python do_swuimage_prepend() {
+    import glob
+
+    if (d.getVar('TRUSTFENCE_SIGN', True) == "1"):
+        d.setVar('SWUPDATE_PRIVATE_KEY', glob.glob(d.getVar('SWUPDATE_PRIVATE_KEY_TEMPLATE', True))[0])
+}
+
 do_unpack[postfuncs] += "fill_description"
 
 fill_description() {
diff --git a/meta-digi-dey/recipes-digi/swu-images/dey-image-qt-swu.bb b/meta-digi-dey/recipes-digi/swu-images/dey-image-qt-swu.bb
index 727b84d38..e79e9cebb 100644
--- a/meta-digi-dey/recipes-digi/swu-images/dey-image-qt-swu.bb
+++ b/meta-digi-dey/recipes-digi/swu-images/dey-image-qt-swu.bb
@@ -38,6 +38,13 @@ python () {
     d.setVarFlag("SWUPDATE_IMAGES_FSTYPES", "dey-image-qt-" + d.getVar('GRAPHICAL_BACKEND', True), img_fstypes)
 }
 
+python do_swuimage_prepend() {
+    import glob
+
+    if (d.getVar('TRUSTFENCE_SIGN', True) == "1"):
+        d.setVar('SWUPDATE_PRIVATE_KEY', glob.glob(d.getVar('SWUPDATE_PRIVATE_KEY_TEMPLATE', True))[0])
+}
+
 do_unpack[postfuncs] += "fill_description"
 
 fill_description() {