diff --git a/include/cglm/vec4.h b/include/cglm/vec4.h
index 0f283ab..8e5bba6 100644
--- a/include/cglm/vec4.h
+++ b/include/cglm/vec4.h
@@ -761,10 +761,10 @@ glm_vec4_addsub(vec4 a, vec4 b, vec4 dest) {
                             vsubq_f32(vld1q_f32(a),
                                       vld1q_f32(b))));
 #else
-  dest[0] += a[0] - b[0];
-  dest[1] += a[1] - b[1];
-  dest[2] += a[2] - b[2];
-  dest[3] += a[3] - b[3];
+  dest[0] -= a[0] + b[0];
+  dest[1] -= a[1] + b[1];
+  dest[2] -= a[2] + b[2];
+  dest[3] -= a[3] + b[3];
 #endif
 }
 
@@ -781,7 +781,7 @@ CGLM_INLINE
 void
 glm_vec4_mulsub(vec4 a, vec4 b, vec4 dest) {
 #if defined(CGLM_SIMD)
-  glmm_store(dest, glmm_fmsub(glmm_load(a), glmm_load(b), glmm_load(dest)));
+  glmm_store(dest, glmm_fnmsub(glmm_load(a), glmm_load(b), glmm_load(dest)));
 #else
   dest[0] -= a[0] * b[0];
   dest[1] -= a[1] * b[1];
@@ -803,7 +803,7 @@ CGLM_INLINE
 void
 glm_vec4_mulsubs(vec4 a, float s, vec4 dest) {
 #if defined(CGLM_SIMD)
-  glmm_store(dest, glmm_fmsub(glmm_load(a), glmm_set1(s), glmm_load(dest)));
+  glmm_store(dest, glmm_fnmsub(glmm_load(a), glmm_set1(s), glmm_load(dest)));
 #else
   dest[0] -= a[0] * s;
   dest[1] -= a[1] * s;