diff --git a/meta/classes-recipe/image.bbclass b/meta/classes-recipe/image.bbclass
index 460e5ab39f..1e3c784ec9 100644
--- a/meta/classes-recipe/image.bbclass
+++ b/meta/classes-recipe/image.bbclass
@@ -127,7 +127,12 @@ def rootfs_command_variables(d):
 python () {
     variables = rootfs_command_variables(d)
     for var in variables:
-        d.setVarFlag(var, 'vardeps', d.getVar(var))
+        value = d.getVar(var)
+        if value and ';' in value:
+            bb.warn("%s contains ';' but is a space separated list of functions, "
+                    "remove the ';' delimiters or the functions will not be part "
+                    "of the task signature: %s" % (var, value.strip()))
+        d.setVarFlag(var, 'vardeps', value)
 }
 
 def rootfs_variables(d):
diff --git a/meta/classes-recipe/populate_sdk_base.bbclass b/meta/classes-recipe/populate_sdk_base.bbclass
index 2c6dd1828c..0d67ab6ac6 100644
--- a/meta/classes-recipe/populate_sdk_base.bbclass
+++ b/meta/classes-recipe/populate_sdk_base.bbclass
@@ -423,7 +423,12 @@ do_populate_sdk[vardeps] += "${@sdk_variables(d)}"
 python () {
     variables = sdk_command_variables(d)
     for var in variables:
-        d.setVarFlag(var, 'vardeps', d.getVar(var))
+        value = d.getVar(var)
+        if value and ';' in value:
+            bb.warn("%s contains ';' but is a space separated list of functions, "
+                    "remove the ';' delimiters or the functions will not be part "
+                    "of the task signature: %s" % (var, value.strip()))
+        d.setVarFlag(var, 'vardeps', value)
 }
 
 do_populate_sdk[file-checksums] += "${TOOLCHAIN_SHAR_REL_TMPL}:True \