diff --git a/include/cglm-mat.h b/include/cglm-mat.h
index d95dbb5..eeab990 100644
--- a/include/cglm-mat.h
+++ b/include/cglm-mat.h
@@ -85,6 +85,30 @@ glm_mat4_pick3(mat4 mat, mat3 dest) {
   dest[2][2] = mat[2][2];
 }
 
+/*!
+ * @brief copy upper-left of mat4 to mat3 (transposed)
+ *
+ * the postfix t stands for transpose
+ *
+ * @param[in]  mat  source
+ * @param[out] dest destination
+ */
+CGLM_INLINE
+void
+glm_mat4_pick3t(mat4 mat, mat3 dest) {
+  dest[0][0] = mat[0][0];
+  dest[0][1] = mat[1][0];
+  dest[0][2] = mat[2][0];
+
+  dest[1][0] = mat[0][1];
+  dest[1][1] = mat[1][1];
+  dest[1][2] = mat[2][1];
+
+  dest[2][0] = mat[0][2];
+  dest[2][1] = mat[1][2];
+  dest[2][2] = mat[2][2];
+}
+
 /*!
  * @brief copy mat3 to mat4's upper-left
  *