diff --git a/test/src/test_affine_mat.h b/test/src/test_affine_mat.h
new file mode 100644
index 0000000..545839b
--- /dev/null
+++ b/test/src/test_affine_mat.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c), Recep Aslantas.
+ *
+ * MIT License (MIT), http://opensource.org/licenses/MIT
+ * Full license can be found in the LICENSE file
+ */
+
+#include "test_common.h"
+
+TEST_IMPL(GLM_PREFIX, mul) {
+  mat4 m1 = GLM_MAT4_IDENTITY_INIT;
+  mat4 m2 = GLM_MAT4_IDENTITY_INIT;
+  mat4 m3;
+  mat4 m4 = GLM_MAT4_ZERO_INIT;
+  int  i, j, k;
+
+  test_rand_mat4(m1);
+  test_rand_mat4(m2);
+
+  GLM(mul)(m1, m2, m3);
+  for (i = 0; i < 4; i++) {
+    for (j = 0; j < 4; j++) {
+      for (k = 0; k < 4; k++)
+        /* column-major */
+        m4[i][j] += m1[k][j] * m2[i][k];
+    }
+  }
+
+  ASSERTIFY(test_assert_mat4_eq(m3, m4))
+
+  /* test pre compiled */
+  GLM(mul)(m1, m2, m3);
+  ASSERTIFY(test_assert_mat4_eq(m3, m4))
+
+  TEST_SUCCESS
+}
+
+TEST_IMPL(GLM_PREFIX, mul_rot) {
+  mat4 m1 = GLM_MAT4_IDENTITY_INIT;
+  mat4 m2 = GLM_MAT4_IDENTITY_INIT;
+  mat4 m3;
+  mat4 m4 = GLM_MAT4_ZERO_INIT;
+  int  i, j, k;
+
+  glm_rotate(m1, drand48(), (vec3){drand48(), drand48(), drand48()});
+  glm_rotate(m2, drand48(), (vec3){drand48(), drand48(), drand48()});
+
+  GLM(mul)(m1, m2, m3);
+  for (i = 0; i < 4; i++) {
+    for (j = 0; j < 4; j++) {
+      for (k = 0; k < 4; k++)
+        /* column-major */
+        m4[i][j] += m1[k][j] * m2[i][k];
+    }
+  }
+
+  ASSERTIFY(test_assert_mat4_eq(m3, m4))
+
+  /* test pre compiled */
+  GLM(mul)(m1, m2, m3);
+  ASSERTIFY(test_assert_mat4_eq(m3, m4))
+
+  TEST_SUCCESS
+}
+
+TEST_IMPL(GLM_PREFIX, inv_tr) {
+  mat4 m1, m2, m3;
+  int  i;
+
+  for (i = 0; i < 10000; i++) {
+    test_rand_mat4(m1);
+
+    glm_mat4_copy(m1, m2);
+
+    /* test inverse precise */
+    GLM(inv_tr)(m1);
+    GLM(inv_tr)(m1);
+    ASSERTIFY(test_assert_mat4_eq(m1, m2))
+
+    /* test inverse precise */
+    GLM(mat4_inv)(m1, m2);
+    GLM(inv_tr)(m2);
+    ASSERTIFY(test_assert_mat4_eq(m1, m2))
+  }
+
+  TEST_SUCCESS
+}
diff --git a/test/src/tests.c b/test/src/tests.c
index 857dea1..ee7c488 100644
--- a/test/src/tests.c
+++ b/test/src/tests.c
@@ -20,6 +20,7 @@
 #include "test_project.h"
 #include "test_plane.h"
 #include "test_affine.h"
+#include "test_affine_mat.h"
 
 #undef GLM
 #undef GLM_PREFIX
@@ -38,6 +39,7 @@
 #include "test_project.h"
 #include "test_plane.h"
 #include "test_affine.h"
+#include "test_affine_mat.h"
 
 #undef GLM
 #undef GLM_PREFIX
diff --git a/test/tests.h b/test/tests.h
index 37475a8..e4933e9 100644
--- a/test/tests.h
+++ b/test/tests.h
@@ -16,6 +16,15 @@
  *   2. use TEST_ENTRY() to add test to list
  */
 
+/* affine mat */
+TEST_DECLARE(glm_mul)
+TEST_DECLARE(glm_mul)
+TEST_DECLARE(glm_inv_tr)
+
+TEST_DECLARE(glmc_mul)
+TEST_DECLARE(glmc_mul_rot)
+TEST_DECLARE(glmc_inv_tr)
+
 /* affine */
 TEST_DECLARE(glm_translate)
 TEST_DECLARE(glm_translate_to)
@@ -579,6 +588,15 @@ TEST_DECLARE(vec4s_zero_init)
 /*****************************************************************************/
 
 TEST_LIST {
+  /* affine mat */
+  TEST_ENTRY(glm_mul)
+  TEST_ENTRY(glm_mul)
+  TEST_ENTRY(glm_inv_tr)
+
+  TEST_ENTRY(glmc_mul)
+  TEST_ENTRY(glmc_mul_rot)
+  TEST_ENTRY(glmc_inv_tr)
+
   /* affine */
   TEST_ENTRY(glm_translate)
   TEST_ENTRY(glm_translate_to)