diff --git a/include/cglm/io.h b/include/cglm/io.h
index d77368b..b95751b 100644
--- a/include/cglm/io.h
+++ b/include/cglm/io.h
@@ -38,7 +38,7 @@
 
 #ifndef cglm_io_h
 #define cglm_io_h
-#if defined(DEBUG) || defined(_DEBUG) \
+#if !defined(NDEBUG) \
    || defined(CGLM_DEFINE_PRINTS) || defined(CGLM_LIB_SRC) \
    || defined(CGLM_NO_PRINTS_NOOP)
 
diff --git a/include/cglm/mat4.h b/include/cglm/mat4.h
index 7f181d1..08310a4 100644
--- a/include/cglm/mat4.h
+++ b/include/cglm/mat4.h
@@ -69,7 +69,7 @@
 #  include "simd/wasm/mat4.h"
 #endif
 
-#ifdef DEBUG
+#ifndef NDEBUG
 # include <assert.h>
 #endif
 
@@ -376,7 +376,7 @@ void
 glm_mat4_mulN(mat4 * __restrict matrices[], uint32_t len, mat4 dest) {
   uint32_t i;
 
-#ifdef DEBUG
+#ifndef NDEBUG
   assert(len > 1 && "there must be least 2 matrices to go!");
 #endif