diff --git a/src/audio/alsa/SDL_alsa_audio.c b/src/audio/alsa/SDL_alsa_audio.c
index fba8d00..5eae5c2 100644
--- a/src/audio/alsa/SDL_alsa_audio.c
+++ b/src/audio/alsa/SDL_alsa_audio.c
@@ -340,7 +340,6 @@
 static void
 no_swizzle(_THIS, void *buffer, Uint32 bufferlen)
 {
-    return;
 }
 #endif /* SND_CHMAP_API_VERSION */
 
diff --git a/src/joystick/SDL_gamecontroller.c b/src/joystick/SDL_gamecontroller.c
index a974bd4..012a459 100644
--- a/src/joystick/SDL_gamecontroller.c
+++ b/src/joystick/SDL_gamecontroller.c
@@ -881,7 +881,7 @@
             for ( pPrevMapping = s_pSupportedControllers, pCurrMapping = pPrevMapping->next;
                   pCurrMapping; 
                   pPrevMapping = pCurrMapping, pCurrMapping = pCurrMapping->next ) {
-                continue;
+                /* continue; */
             }
             pPrevMapping->next = pControllerMapping;
         } else {
diff --git a/src/render/opengl/SDL_render_gl.c b/src/render/opengl/SDL_render_gl.c
index 06f69b4..ed6da08 100644
--- a/src/render/opengl/SDL_render_gl.c
+++ b/src/render/opengl/SDL_render_gl.c
@@ -180,7 +180,7 @@
         }
     } else if (data->glGetError != NULL) {
         while (data->glGetError() != GL_NO_ERROR) {
-            continue;
+            /* continue; */
         }
     }
 }
diff --git a/src/render/opengles2/SDL_render_gles2.c b/src/render/opengles2/SDL_render_gles2.c
index e035c1f..e7425e4 100644
--- a/src/render/opengles2/SDL_render_gles2.c
+++ b/src/render/opengles2/SDL_render_gles2.c
@@ -208,7 +208,7 @@
         return;
     }
     while (data->glGetError() != GL_NO_ERROR) {
-        continue;
+        /* continue; */
     }
 }
 
diff --git a/src/video/SDL_blit_N.c b/src/video/SDL_blit_N.c
index 9313ee6..8950e36 100644
--- a/src/video/SDL_blit_N.c
+++ b/src/video/SDL_blit_N.c
@@ -2317,7 +2317,6 @@
     if (_alpha_channel) {
         *_alpha_channel = alpha_channel;
     }
-    return;
 }
 
 
@@ -3109,7 +3108,6 @@
             dst += dstskip;
         }
     }
-    return;
 }
 
 /* Blit_3or4_to_3or4__inversed_rgb: 3 or 4 bpp, inversed RGB triplet */
@@ -3214,7 +3212,6 @@
             dst += dstskip;
         }
     }
-    return;
 }
 
 /* Normal N to N optimized blitters */
diff --git a/src/video/wayland/SDL_waylandtouch.c b/src/video/wayland/SDL_waylandtouch.c
index 16d911e..ba913ef 100644
--- a/src/video/wayland/SDL_waylandtouch.c
+++ b/src/video/wayland/SDL_waylandtouch.c
@@ -192,7 +192,6 @@
 /* wayland-qt-windowmanager.c ENDS */
 
 /* wayland-qt-surface-extension.c BEGINS */
-extern const struct wl_interface qt_extended_surface_interface;
 #ifndef SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC
 extern const struct wl_interface wl_surface_interface;
 #endif