diff --git a/auto/os/features b/auto/os/features
index e8ae033d0..670de98a0 100644
--- a/auto/os/features
+++ b/auto/os/features
@@ -4,24 +4,25 @@
 
 NGX_USER=${NGX_USER:-nobody}
 
-if [ -z "$NGX_GROUP" -a $NGX_USER = nobody ] ; then
-    if grep nobody /etc/group 2>&1 >/dev/null; then
-        echo "checking for nobody group ... found"
-        NGX_GROUP=nobody
-    else
-        echo "checking for nobody group ... not found"
-
-        if grep nogroup /etc/group 2>&1 >/dev/null; then
-            echo "checking for nogroup group ... found"
-            NGX_GROUP=nogroup
-        else
-            echo "checking for nogroup group ... not found"
+if [ -z "$NGX_GROUP" ]; then
+    if [ $NGX_USER = nobody ]; then
+        if grep nobody /etc/group 2>&1 >/dev/null; then
+            echo "checking for nobody group ... found"
             NGX_GROUP=nobody
-        fi
-    fi
+        else
+            echo "checking for nobody group ... not found"
 
-else
-    NGX_GROUP=$NGX_USER
+            if grep nogroup /etc/group 2>&1 >/dev/null; then
+                echo "checking for nogroup group ... found"
+                NGX_GROUP=nogroup
+            else
+                echo "checking for nogroup group ... not found"
+                NGX_GROUP=nobody
+            fi
+        fi
+    else
+        NGX_GROUP=$NGX_USER
+    fi
 fi