diff --git a/core/object.h b/core/object.h
index f9e8755e062..b23160c1df1 100644
--- a/core/object.h
+++ b/core/object.h
@@ -422,7 +422,7 @@ private:
 	};
 
 #ifdef DEBUG_ENABLED
-	friend class _ObjectDebugLock;
+	friend struct _ObjectDebugLock;
 #endif
 	friend bool predelete_handler(Object *);
 	friend void postinitialize_handler(Object *);
diff --git a/core/variant.h b/core/variant.h
index 2fffb31de66..89532177606 100644
--- a/core/variant.h
+++ b/core/variant.h
@@ -116,7 +116,7 @@ public:
 	};
 
 private:
-	friend class _VariantCall;
+	friend struct _VariantCall;
 	// Variant takes 20 bytes when real_t is float, and 36 if double
 	// it only allocates extra memory for aabb/matrix.
 
diff --git a/drivers/gles3/rasterizer_storage_gles3.h b/drivers/gles3/rasterizer_storage_gles3.h
index b31c5ff7bb7..9a4798ac2a1 100644
--- a/drivers/gles3/rasterizer_storage_gles3.h
+++ b/drivers/gles3/rasterizer_storage_gles3.h
@@ -691,7 +691,7 @@ public:
 		}
 	};
 
-	class MultiMesh;
+	struct MultiMesh;
 
 	struct Mesh : public GeometryOwner {
 
diff --git a/editor/editor_export.h b/editor/editor_export.h
index 420f383f95d..b4ee5b89e74 100644
--- a/editor/editor_export.h
+++ b/editor/editor_export.h
@@ -37,10 +37,10 @@
 #include "scene/main/timer.h"
 #include "scene/resources/texture.h"
 
-class EditorProgress;
 class FileAccess;
 class EditorExportPlatform;
 class EditorFileSystemDirectory;
+struct EditorProgress;
 
 class EditorExportPreset : public Reference {
 
diff --git a/modules/bullet/rigid_body_bullet.h b/modules/bullet/rigid_body_bullet.h
index cd2f215906a..25dac309514 100644
--- a/modules/bullet/rigid_body_bullet.h
+++ b/modules/bullet/rigid_body_bullet.h
@@ -227,7 +227,7 @@ public:
 
 	void init_kinematic_utilities();
 	void destroy_kinematic_utilities();
-	_FORCE_INLINE_ class KinematicUtilities *get_kinematic_utilities() const { return kinematic_utilities; }
+	_FORCE_INLINE_ KinematicUtilities *get_kinematic_utilities() const { return kinematic_utilities; }
 
 	_FORCE_INLINE_ btRigidBody *get_bt_rigid_body() { return btBody; }
 
diff --git a/modules/bullet/space_bullet.h b/modules/bullet/space_bullet.h
index d815898ffd2..c3d55cbbb1f 100644
--- a/modules/bullet/space_bullet.h
+++ b/modules/bullet/space_bullet.h
@@ -57,7 +57,7 @@ class btDiscreteDynamicsWorld;
 class btEmptyShape;
 class btGhostPairCallback;
 class btSoftRigidDynamicsWorld;
-class btSoftBodyWorldInfo;
+struct btSoftBodyWorldInfo;
 class ConstraintBullet;
 class CollisionObjectBullet;
 class RigidBodyBullet;
diff --git a/scene/resources/world.h b/scene/resources/world.h
index 4c517323f37..4ba6b134768 100644
--- a/scene/resources/world.h
+++ b/scene/resources/world.h
@@ -36,9 +36,9 @@
 #include "servers/physics_server.h"
 #include "servers/visual_server.h"
 
-class SpatialIndexer;
 class Camera;
 class VisibilityNotifier;
+struct SpatialIndexer;
 
 class World : public Resource {
 	GDCLASS(World, Resource);
diff --git a/scene/resources/world_2d.cpp b/scene/resources/world_2d.cpp
index b390e74073a..dd78d04104a 100644
--- a/scene/resources/world_2d.cpp
+++ b/scene/resources/world_2d.cpp
@@ -29,13 +29,13 @@
 /*************************************************************************/
 
 #include "world_2d.h"
-#include "servers/physics_2d_server.h"
-#include "servers/visual_server.h"
-//#include "servers/spatial_sound_2d_server.h"
+
 #include "core/project_settings.h"
 #include "scene/2d/camera_2d.h"
 #include "scene/2d/visibility_notifier_2d.h"
 #include "scene/main/viewport.h"
+#include "servers/physics_2d_server.h"
+#include "servers/visual_server.h"
 
 struct SpatialIndexer2D {
 
diff --git a/scene/resources/world_2d.h b/scene/resources/world_2d.h
index 856e9dbf015..88ad392f85e 100644
--- a/scene/resources/world_2d.h
+++ b/scene/resources/world_2d.h
@@ -35,9 +35,9 @@
 #include "core/resource.h"
 #include "servers/physics_2d_server.h"
 
-class SpatialIndexer2D;
 class VisibilityNotifier2D;
 class Viewport;
+struct SpatialIndexer2D;
 
 class World2D : public Resource {
 
diff --git a/servers/audio/reverb_sw.cpp b/servers/audio/reverb_sw.cpp
index 13742d5db5d..d078da38b44 100644
--- a/servers/audio/reverb_sw.cpp
+++ b/servers/audio/reverb_sw.cpp
@@ -29,33 +29,21 @@
 /*************************************************************************/
 
 #include "reverb_sw.h"
+
 #include "core/print_string.h"
-#include "stdlib.h"
+
+#include <stdlib.h>
+
 #define SETMIN(x, y) (x) = MIN((x), (y))
+
 #define rangeloop(c, min, max) \
 	for ((c) = (min); (c) < (max); (c)++)
 
 #define ABSDIFF(x, y) \
 	(((x) < (y)) ? ((y) - (x)) : ((x) - (y)))
 
-#ifdef bleh_MSC_VER
-
-#if _MSC_VER >= 1400
-_FORCE_INLINE_ int32_tMULSHIFT_S32(
-		int32_t Factor1,
-		int32_t Factor2,
-		uint8_t Bits) {
-
-	return __ll_rshift(
-			__emul(Factor1, Factor2),
-			Bits);
-}
-#endif
-
-#else
 #define MULSHIFT_S32(Factor1, Factor2, Bits) \
 	((int)(((int64_t)(Factor1) * (Factor2)) >> (Bits)))
-#endif
 
 struct ReverbParamsSW {
 	unsigned int BufferSize; // Required buffer size
diff --git a/servers/audio/reverb_sw.h b/servers/audio/reverb_sw.h
index 26b3fa5166e..01977d1f615 100644
--- a/servers/audio/reverb_sw.h
+++ b/servers/audio/reverb_sw.h
@@ -34,7 +34,7 @@
 #include "core/os/memory.h"
 #include "core/typedefs.h"
 
-class ReverbParamsSW;
+struct ReverbParamsSW;
 
 class ReverbSW {
 public: