diff --git a/include/cglm/call/project.h b/include/cglm/call/project.h
index c60b9b3..35ac087 100644
--- a/include/cglm/call/project.h
+++ b/include/cglm/call/project.h
@@ -15,11 +15,15 @@ extern "C" {
 
 CGLM_EXPORT
 void
-glmc_unprojecti(mat4 invMat, vec4 vp, vec3 coord, vec3 dest);
+glmc_unprojecti(vec3 pos, mat4 invMat, vec4 vp, vec3 dest);
 
 CGLM_EXPORT
 void
-glmc_unproject(mat4 m, vec4 vp, vec3 coord, vec3 dest);
+glmc_unproject(vec3 pos, mat4 m, vec4 vp, vec3 dest);
+
+CGLM_EXPORT
+void
+glmc_project(vec3 pos, mat4 m, vec4 vp, vec3 dest);
 
 #ifdef __cplusplus
 }
diff --git a/include/cglm/project.h b/include/cglm/project.h
index fdb0cf9..a0b306b 100644
--- a/include/cglm/project.h
+++ b/include/cglm/project.h
@@ -33,23 +33,24 @@
  *   glm_mat4_mul(viewProj, model, MVP);
  *   glm_mat4_inv(viewProj, invMVP);
  *
+ * @param[in]  pos    viewport coordinates
  * @param[in]  invMat   matrix (see brief)
  * @param[in]  vp       viewport as [x, y, width, height]
- * @param[in]  coord    viewport coordinates
  * @param[out] dest     unprojected coordinates
  */
 CGLM_INLINE
 void
-glm_unprojecti(mat4 invMat, vec4 vp, vec3 coord, vec4 dest) {
+glm_unprojecti(vec3 pos, mat4 invMat, vec4 vp, vec3 dest) {
   vec4 v;
 
-  v[0] = 2.0f * (coord[0] - vp[0]) / vp[2] - 1.0f;
-  v[1] = 2.0f * (coord[1] - vp[1]) / vp[3] - 1.0f;
-  v[2] = 2.0f *  coord[2]                  - 1.0f;
+  v[0] = 2.0f * (pos[0] - vp[0]) / vp[2] - 1.0f;
+  v[1] = 2.0f * (pos[1] - vp[1]) / vp[3] - 1.0f;
+  v[2] = 2.0f *  pos[2]                  - 1.0f;
   v[3] = 1.0f;
 
   glm_mat4_mulv(invMat, v, v);
-  glm_vec4_scale(v, 1.0f / v[3], dest);
+  glm_vec4_scale(v, 1.0f / v[3], v);
+  glm_vec3(v, dest);
 }
 
 /*!
@@ -71,17 +72,17 @@ glm_unprojecti(mat4 invMat, vec4 vp, vec3 coord, vec4 dest) {
  *   glm_mat4_mul(proj, view, viewProj);
  *   glm_mat4_mul(viewProj, model, MVP);
  *
+ * @param[in]  pos      viewport coordinates
  * @param[in]  m        matrix (see brief)
  * @param[in]  vp       viewport as [x, y, width, height]
- * @param[in]  coord    viewport coordinates
  * @param[out] dest     unprojected coordinates
  */
 CGLM_INLINE
 void
-glm_unproject(mat4 m, vec4 vp, vec3 coord, vec4 dest) {
+glm_unproject(vec3 pos, mat4 m, vec4 vp, vec3 dest) {
   mat4 inv;
   glm_mat4_inv(m, inv);
-  glm_unprojecti(inv, vp, coord, dest);
+  glm_unprojecti(pos, inv, vp, dest);
 }
 
 /*!
diff --git a/src/project.c b/src/project.c
index 16209e7..91c7128 100644
--- a/src/project.c
+++ b/src/project.c
@@ -10,12 +10,18 @@
 
 CGLM_EXPORT
 void
-glmc_unprojecti(mat4 invMat, vec4 vp, vec3 coord, vec3 dest) {
-  glm_unprojecti(invMat, vp, coord, dest);
+glmc_unprojecti(vec3 pos, mat4 invMat, vec4 vp, vec3 dest) {
+  glm_unprojecti(pos, invMat, vp, dest);
 }
 
 CGLM_EXPORT
 void
-glmc_unproject(mat4 m, vec4 vp, vec3 coord, vec3 dest) {
-  glm_unproject(m, vp, coord, dest);
+glmc_unproject(vec3 pos, mat4 m, vec4 vp, vec3 dest) {
+  glm_unproject(pos, m, vp, dest);
+}
+
+CGLM_EXPORT
+void
+glmc_project(vec3 pos, mat4 m, vec4 vp, vec3 dest) {
+  glm_project(pos, m, vp, dest);
 }
diff --git a/test/src/test_main.c b/test/src/test_main.c
index 5d59cfd..61fa7d5 100644
--- a/test/src/test_main.c
+++ b/test/src/test_main.c
@@ -15,6 +15,9 @@ main(int argc, const char * argv[]) {
     /* camera */
     cmocka_unit_test(test_camera_lookat),
     cmocka_unit_test(test_camera_decomp)
+
+    /* project */
+    cmocka_unit_test(test_project)
   };
 
   return cmocka_run_group_tests(tests, NULL, NULL);
diff --git a/test/src/test_project.c b/test/src/test_project.c
new file mode 100644
index 0000000..4cdac9e
--- /dev/null
+++ b/test/src/test_project.c
@@ -0,0 +1,31 @@
+/*
+ * 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"
+
+void
+test_project(void **state) {
+  mat4 model, view, proj, mvp;
+  vec4 viewport = {0.0f, 0.0f, 800.0f, 600.0f};
+  vec3 pos      = {13.0f, 45.0f, 0.74f};
+  vec3 projected, unprojected;
+
+  glm_translate_make(model, (vec3){0.0f, 0.0f, -10.0f});
+  glm_lookat((vec3){0.0f, 0.0f, 0.0f}, pos, GLM_YUP, view);
+
+  glm_perspective_default(0.5f, proj);
+  glm_mat4_mulN((mat4 *[]){&proj, &view, &model}, 3, mvp);
+
+  glmc_project(pos, mvp, viewport, projected);
+  glmc_unproject(projected, mvp, viewport, unprojected);
+
+  /* unprojected of projected vector must be same as original one */
+  /* we used 0.01 because of projection floating point errors */
+  assert_true(fabsf(pos[0] - unprojected[0]) < 0.01);
+  assert_true(fabsf(pos[1] - unprojected[1]) < 0.01);
+  assert_true(fabsf(pos[2] - unprojected[2]) < 0.01);
+}
diff --git a/test/src/test_tests.h b/test/src/test_tests.h
index a4e5adb..26eb91d 100644
--- a/test/src/test_tests.h
+++ b/test/src/test_tests.h
@@ -16,4 +16,7 @@ test_camera_lookat(void **state);
 void
 test_camera_decomp(void **state);
 
+void
+test_project(void **state);
+
 #endif /* test_tests_h */