diff --git a/include/reactphysics3d/collision/ContactManifold.h b/include/reactphysics3d/collision/ContactManifold.h
index 3e4c546a..b5f74d7e 100644
--- a/include/reactphysics3d/collision/ContactManifold.h
+++ b/include/reactphysics3d/collision/ContactManifold.h
@@ -34,7 +34,7 @@ namespace reactphysics3d {
 
 // Class declarations
 class ContactManifold;
-class ContactManifoldInfo;
+struct ContactManifoldInfo;
 struct ContactPointInfo;
 class CollisionBody;
 class ContactPoint;
diff --git a/include/reactphysics3d/collision/narrowphase/GJK/GJKAlgorithm.h b/include/reactphysics3d/collision/narrowphase/GJK/GJKAlgorithm.h
index 86d1676f..04eb764b 100644
--- a/include/reactphysics3d/collision/narrowphase/GJK/GJKAlgorithm.h
+++ b/include/reactphysics3d/collision/narrowphase/GJK/GJKAlgorithm.h
@@ -34,7 +34,7 @@
 namespace reactphysics3d {
 
 // Declarations
-class ContactManifoldInfo;
+struct ContactManifoldInfo;
 struct NarrowPhaseInfoBatch;
 class ConvexShape;
 class Profiler;
diff --git a/include/reactphysics3d/collision/narrowphase/NarrowPhaseAlgorithm.h b/include/reactphysics3d/collision/narrowphase/NarrowPhaseAlgorithm.h
index c360b2bc..2cdcd69f 100644
--- a/include/reactphysics3d/collision/narrowphase/NarrowPhaseAlgorithm.h
+++ b/include/reactphysics3d/collision/narrowphase/NarrowPhaseAlgorithm.h
@@ -33,7 +33,7 @@
 namespace reactphysics3d {
 
 class CollisionDetectionSystem;
-class ContactManifoldInfo;
+struct ContactManifoldInfo;
 class DefaultPoolAllocator;
 class OverlappingPair;
 struct NarrowPhaseInfoBatch;
diff --git a/include/reactphysics3d/collision/narrowphase/NarrowPhaseInfoBatch.h b/include/reactphysics3d/collision/narrowphase/NarrowPhaseInfoBatch.h
index 3a401116..4f597bd7 100644
--- a/include/reactphysics3d/collision/narrowphase/NarrowPhaseInfoBatch.h
+++ b/include/reactphysics3d/collision/narrowphase/NarrowPhaseInfoBatch.h
@@ -35,7 +35,7 @@ namespace reactphysics3d {
 // Declarations
 class CollisionShape;
 struct LastFrameCollisionInfo;
-class ContactManifoldInfo;
+struct ContactManifoldInfo;
 struct ContactPointInfo;
 
 // Struct NarrowPhaseInfoBatch
diff --git a/include/reactphysics3d/collision/narrowphase/SAT/SATAlgorithm.h b/include/reactphysics3d/collision/narrowphase/SAT/SATAlgorithm.h
index 095ef344..2d7000cc 100644
--- a/include/reactphysics3d/collision/narrowphase/SAT/SATAlgorithm.h
+++ b/include/reactphysics3d/collision/narrowphase/SAT/SATAlgorithm.h
@@ -36,7 +36,7 @@ namespace reactphysics3d {
 // Declarations
 class CapsuleShape;
 class SphereShape;
-class ContactManifoldInfo;
+struct ContactManifoldInfo;
 struct NarrowPhaseInfoBatch;
 class ConvexPolyhedronShape;
 class MemoryAllocator;