diff --git a/completions/make b/completions/make
index f1226675b9d..24f00f18f54 100644
--- a/completions/make
+++ b/completions/make
@@ -199,11 +199,7 @@ _make()
                     paths[$path]=1 &&
                     [[ $path == "$prefix"*/* ]]; do
                     path=${path%/*}
-                    if [[ ! ${nchild[$path]+set} ]]; then
-                        ((nchild[\$path] = 1))
-                    else
-                        ((nchild[\$path]++))
-                    fi
+                    nchild[$path]=$((${nchild[$path]-0} + 1))
                 done
             done