diff --git a/meta/classes-recipe/crosssdk.bbclass b/meta/classes-recipe/crosssdk.bbclass
index f7be3a23bf6..6246c09de4b 100644
--- a/meta/classes-recipe/crosssdk.bbclass
+++ b/meta/classes-recipe/crosssdk.bbclass
@@ -16,8 +16,7 @@ PACKAGE_ARCH = "${SDK_ARCH}"
 python () {
     # set TUNE_PKGARCH to SDK_ARCH
     d.setVar('TUNE_PKGARCH', d.getVar('SDK_ARCH'))
-    defaults = d.getVar("DISTRO_FEATURES")
-    d.setVar("DISTRO_FEATURES", '${@oe.utils.class_filter_features("' + defaults + '", "DISTRO_FEATURES_NATIVESDK", "DISTRO_FEATURES_FILTER_NATIVESDK", d)}')
+    oe.utils.set_class_filter("DISTRO_FEATURES", "DISTRO_FEATURES_NATIVESDK", "DISTRO_FEATURES_FILTER_NATIVESDK", d)
 }
 
 STAGING_BINDIR_TOOLCHAIN = "${STAGING_DIR_NATIVE}${bindir_native}/${TARGET_ARCH}${TARGET_VENDOR}-${TARGET_OS}"
diff --git a/meta/classes-recipe/native.bbclass b/meta/classes-recipe/native.bbclass
index 6b334e782a4..b357b2da7b9 100644
--- a/meta/classes-recipe/native.bbclass
+++ b/meta/classes-recipe/native.bbclass
@@ -126,8 +126,7 @@ python native_virtclass_handler () {
         return
     bpn = d.getVar("BPN")
 
-    defaults = d.getVar("DISTRO_FEATURES")
-    d.setVar("DISTRO_FEATURES", '${@oe.utils.class_filter_features("' + defaults + '", "DISTRO_FEATURES_NATIVE", "DISTRO_FEATURES_FILTER_NATIVE", d)}')
+    oe.utils.set_class_filter("DISTRO_FEATURES", "DISTRO_FEATURES_NATIVE", "DISTRO_FEATURES_FILTER_NATIVE", d)
 
     classextend = d.getVar('BBCLASSEXTEND') or ""
     if "native" not in classextend:
diff --git a/meta/classes-recipe/nativesdk.bbclass b/meta/classes-recipe/nativesdk.bbclass
index 25fd463ac78..5b49affd537 100644
--- a/meta/classes-recipe/nativesdk.bbclass
+++ b/meta/classes-recipe/nativesdk.bbclass
@@ -77,8 +77,7 @@ python nativesdk_virtclass_handler () {
     if not (pn.endswith("-nativesdk") or pn.startswith("nativesdk-")):
         return
 
-    defaults = d.getVar("DISTRO_FEATURES")
-    d.setVar("DISTRO_FEATURES", '${@oe.utils.class_filter_features("' + defaults + '", "DISTRO_FEATURES_NATIVESDK", "DISTRO_FEATURES_FILTER_NATIVESDK", d)}')
+    oe.utils.set_class_filter("DISTRO_FEATURES", "DISTRO_FEATURES_NATIVESDK", "DISTRO_FEATURES_FILTER_NATIVESDK", d)
 
     e.data.setVar("MLPREFIX", "nativesdk-")
     e.data.setVar("PN", "nativesdk-" + e.data.getVar("PN").replace("-nativesdk", "").replace("nativesdk-", ""))
diff --git a/meta/lib/oe/utils.py b/meta/lib/oe/utils.py
index 23f4b639c69..120b6443935 100644
--- a/meta/lib/oe/utils.py
+++ b/meta/lib/oe/utils.py
@@ -161,6 +161,15 @@ def class_filter_features(defaults, features_var, filter_var, d):
     filtered = set(bb.utils.filter_string(defaults, d.getVar(filter_var)).split())
     return " ".join(sorted(features | filtered))
 
+def set_class_filter(var, features_var, filter_var, d):
+    defaults = d.getVar(var)
+    if "}" in defaults:
+        issues = [c for c in defaults.split() if "}" in c]
+        for issue in issues:
+            defaults = defaults.replace(issue, "")
+            bb.warn("Unexpanded variable %s in %s is not recommended" % (issue, var))
+    d.setVar(var, '${@oe.utils.class_filter_features("' + defaults + '", "' + features_var + '", "' + filter_var + '", d)}')
+
 def all_distro_features(d, features, truevalue="1", falsevalue=""):
     """
     Returns truevalue if *all* given features are set in DISTRO_FEATURES,