diff --git a/src/gl/MiniFB_GL.c b/src/gl/MiniFB_GL.c
index 737c010..b743244 100644
--- a/src/gl/MiniFB_GL.c
+++ b/src/gl/MiniFB_GL.c
@@ -203,6 +203,18 @@ init_GL(SWindowData *window_data) {
 void 
 resize_GL(SWindowData *window_data) {
     if(window_data->is_initialized) {
+    #if defined(_WIN32) || defined(WIN32)
+
+        SWindowData_Win *window_data_ex = (SWindowData_Win *) window_data->specific;
+        wglMakeCurrent(window_data_ex->hdc, window_data_ex->hGLRC);
+
+    #elif defined(linux)
+
+        SWindowData_X11 *window_data_ex = (SWindowData_X11 *) window_data->specific;
+        glXMakeCurrent(window_data_ex->display, window_data_ex->window, window_data_ex->context);
+
+    #endif
+
         glViewport(0, 0, window_data->window_width, window_data->window_height);
 
         glMatrixMode(GL_PROJECTION);
@@ -221,11 +233,15 @@ redraw_GL(SWindowData *window_data, const void *pixels) {
     SWindowData_Win *window_data_ex = (SWindowData_Win *) window_data->specific;
     GLenum format = BGRA;
 
+    wglMakeCurrent(window_data_ex->hdc, window_data_ex->hGLRC);
+
 #elif defined(linux)
 
     SWindowData_X11 *window_data_ex = (SWindowData_X11 *) window_data->specific;
     GLenum format = BGRA;
 
+    glXMakeCurrent(window_data_ex->display, window_data_ex->window, window_data_ex->context);
+
 #endif
 
     float           x, y, w, h;
diff --git a/tests/hidpi.c b/tests/hidpi.c
index 3cf2c1b..4053a89 100644
--- a/tests/hidpi.c
+++ b/tests/hidpi.c
@@ -1,7 +1,6 @@
 #include <MiniFB.h>
 #include <stdio.h>
 #include <stdint.h>
-#include <unistd.h>
 #include <string.h>
 
 #define DIMEN_LOW      512
@@ -11,38 +10,35 @@ static unsigned int g_buffer_low[DIMEN_LOW * DIMEN_LOW];
 static unsigned int g_buffer_high[DIMEN_HIGH * DIMEN_HIGH];
 
 void
-pretty_square(unsigned int *p, int dimen)
-{
-  memset(p, 127, dimen*dimen*4);
-  const int one_half_dimen = dimen / 2;
-  const int one_quarter_dimen = one_half_dimen / 2;
-  const int three_quarter_dimen = one_half_dimen + one_quarter_dimen;
-  for (int x = one_quarter_dimen; x < three_quarter_dimen; x++)
-    for (int y = one_quarter_dimen; y < three_quarter_dimen; y++)
-      p[y*dimen + x] = (x & 1) ? MFB_RGB(223,0,(255*(x-one_quarter_dimen))/one_half_dimen) : MFB_RGB(0,0,0);
+pretty_square(unsigned int *p, int dimen) {
+    memset(p, 127, dimen * dimen * 4);
+    const int one_half_dimen = dimen / 2;
+    const int one_quarter_dimen = one_half_dimen / 2;
+    const int three_quarter_dimen = one_half_dimen + one_quarter_dimen;
+    for (int x = one_quarter_dimen; x < three_quarter_dimen; x++)
+        for (int y = one_quarter_dimen; y < three_quarter_dimen; y++)
+            p[y * dimen + x] = (x & 1) ? MFB_RGB(223, 0, (255 * (x - one_quarter_dimen)) / one_half_dimen) : MFB_RGB(0, 0, 0);
 }
 
-int 
-main()
-{
-  pretty_square(g_buffer_low, DIMEN_LOW);
-  pretty_square(g_buffer_high, DIMEN_HIGH);
+int
+main() {
+    pretty_square(g_buffer_low, DIMEN_LOW);
+    pretty_square(g_buffer_high, DIMEN_HIGH);
 
-  struct mfb_window *window_low = mfb_open("LowRes", DIMEN_LOW, DIMEN_LOW);
-  struct mfb_window *window_high = mfb_open("HighRes", DIMEN_HIGH/2, DIMEN_HIGH/2);
+    struct mfb_window *window_low  = mfb_open("LowRes", DIMEN_LOW, DIMEN_LOW);
+    struct mfb_window *window_high = mfb_open("HighRes", DIMEN_HIGH / 2, DIMEN_HIGH / 2);
 
-  while (window_high || window_low)
-    {
-      if (window_low)
-	if (mfb_update_ex(window_low, g_buffer_low, DIMEN_LOW, DIMEN_LOW) != STATE_OK
-	      || !mfb_wait_sync(window_low))
-	    window_low = NULL;
+    while (window_high || window_low) {
+        if (window_low)
+            if (mfb_update_ex(window_low, g_buffer_low, DIMEN_LOW, DIMEN_LOW) != STATE_OK
+                || !mfb_wait_sync(window_low))
+                window_low = NULL;
 
-      if (window_high)
-	if (mfb_update_ex(window_high, g_buffer_high, DIMEN_HIGH, DIMEN_HIGH) != STATE_OK
-	    || !mfb_wait_sync(window_high))
-	  window_high = NULL;
+        if (window_high)
+            if (mfb_update_ex(window_high, g_buffer_high, DIMEN_HIGH, DIMEN_HIGH) != STATE_OK
+                || !mfb_wait_sync(window_high))
+                window_high = NULL;
     }
-  
-  return 0;
+
+    return 0;
 }