diff --git a/gfx/d3d9/d3d9.cpp b/gfx/d3d9/d3d9.cpp
index a59aa5647c..608a676dba 100644
--- a/gfx/d3d9/d3d9.cpp
+++ b/gfx/d3d9/d3d9.cpp
@@ -363,17 +363,17 @@ void D3DVideo::calculate_rect(unsigned width, unsigned height,
       else
       {
          float device_aspect = static_cast<float>(width) / static_cast<float>(height);
-         if (fabs(device_aspect - desired_aspect) < 0.0001)
+         if (fabsf(device_aspect - desired_aspect) < 0.0001f)
             set_viewport(0, 0, width, height);
          else if (device_aspect > desired_aspect)
          {
-            float delta = (desired_aspect / device_aspect - 1.0) / 2.0 + 0.5;
-            set_viewport(width * (0.5 - delta), 0, 2.0 * width * delta, height);
+            float delta = (desired_aspect / device_aspect - 1.0f) / 2.0f + 0.5f;
+            set_viewport(int(roundf(width * (0.5f - delta))), 0, unsigned(roundf(2.0f * width * delta)), height);
          }
          else
          {
-            float delta = (device_aspect / desired_aspect - 1.0) / 2.0 + 0.5;
-            set_viewport(0, height * (0.5 - delta), width, 2.0 * height * delta);
+            float delta = (device_aspect / desired_aspect - 1.0f) / 2.0f + 0.5f;
+            set_viewport(0, int(roundf(height * (0.5f - delta))), width, unsigned(roundf(2.0f * height * delta)));
          }
       }
    }
diff --git a/gfx/gl.c b/gfx/gl.c
index 0a0e03887f..bc55404724 100644
--- a/gfx/gl.c
+++ b/gfx/gl.c
@@ -783,22 +783,22 @@ void gl_set_viewport(void *data, unsigned width, unsigned height, bool force_ful
       else
 #endif
       {
-         if (fabs(device_aspect - desired_aspect) < 0.0001)
+         if (fabsf(device_aspect - desired_aspect) < 0.0001f)
          {
             // If the aspect ratios of screen and desired aspect ratio are sufficiently equal (floating point stuff), 
             // assume they are actually equal.
          }
          else if (device_aspect > desired_aspect)
          {
-            delta = (desired_aspect / device_aspect - 1.0) / 2.0 + 0.5;
-            x     = (unsigned)(width * (0.5 - delta));
-            width = (unsigned)(2.0 * width * delta);
+            delta = (desired_aspect / device_aspect - 1.0f) / 2.0f + 0.5f;
+            x     = (int)roundf(width * (0.5f - delta));
+            width = (unsigned)roundf(2.0f * width * delta);
          }
          else
          {
-            delta  = (device_aspect / desired_aspect - 1.0) / 2.0 + 0.5;
-            y      = (unsigned)(height * (0.5 - delta));
-            height = (unsigned)(2.0 * height * delta);
+            delta  = (device_aspect / desired_aspect - 1.0f) / 2.0f + 0.5f;
+            y      = (int)roundf(height * (0.5f - delta));
+            height = (unsigned)roundf(2.0f * height * delta);
          }
       }