diff --git a/common_power.h b/common_power.h
index 6fb2af30a..a49197fd7 100644
--- a/common_power.h
+++ b/common_power.h
@@ -849,8 +849,8 @@ Lmcount$lazy_ptr:
 #else
 #define BUFFER_SIZE     ( 16 << 20)
 #endif
-#ifeq ($(DYNAMIC_ARCH), 1)
-#undefine BUFFER_SIZE
+#ifdef DYNAMIC_ARCH
+#undef BUFFER_SIZE
 #define BUFFER_SIZE (64 << 22)
 #endif