diff --git a/nall/GNUmakefile b/nall/GNUmakefile
index 7c43e3db..3e1df801 100755
--- a/nall/GNUmakefile
+++ b/nall/GNUmakefile
@@ -34,15 +34,17 @@ ifeq ($(platform),)
   else
     $(error unknown platform, please specify manually.)
   endif
+endif
 
-  # common commands
-  ifeq ($(uname),)
-    delete  = $(info Deleting $1 ...) @del /q $(subst /,\,$1)
-    rdelete = $(info Deleting $1 ...) @del /s /q $(subst /,\,$1) && if exist $(subst /,\,$1) (rmdir /s /q $(subst /,\,$1))
-  else
-    delete  = $(info Deleting $1 ...) @rm -f $1
-    rdelete = $(info Deleting $1 ...) @rm -rf $1
-  endif
+# common commands
+ifeq ($(shell echo ^^),^)
+  # cmd
+  delete  = $(info Deleting $1 ...) @del /q $(subst /,\,$1)
+  rdelete = $(info Deleting $1 ...) @del /s /q $(subst /,\,$1) && if exist $(subst /,\,$1) (rmdir /s /q $(subst /,\,$1))
+else
+  # sh
+  delete  = $(info Deleting $1 ...) @rm -f $1
+  rdelete = $(info Deleting $1 ...) @rm -rf $1
 endif
 
 compiler.c      = $(compiler) -x c -std=c11