diff --git a/configure b/configure
index 7e523c50..13fc5049 100755
--- a/configure
+++ b/configure
@@ -200,6 +200,8 @@ if [ -n "$DEBUG" -a "$DEBUG" != no -a "$DEBUG" != false ]; then
 	echo "Building with debugging symbols."
 	echo "CPPFLAGS += -DDEBUG" >>$CONFIG_MK
 	echo "CFLAGS +=	-g" >>$CONFIG_MK
+else
+	echo "CPPFLAGS+= -DNDEBUG" >>$CONFIG_MK
 fi
 
 case "$OS" in
diff --git a/include/xbps_api_impl.h b/include/xbps_api_impl.h
index 32422e61..fcb2dd4a 100644
--- a/include/xbps_api_impl.h
+++ b/include/xbps_api_impl.h
@@ -27,10 +27,6 @@
 #ifndef _XBPS_API_IMPL_H_
 #define _XBPS_API_IMPL_H_
 
-#ifndef DEBUG
-#define NDEBUG
-#endif
-
 #include <assert.h>
 #include <confuse.h>
 #define LIBXBPS_PRIVATE