diff --git a/src/common/rendering/hwrenderer/data/hw_bonebuffer.cpp b/src/common/rendering/hwrenderer/data/hw_bonebuffer.cpp
index 9d465d417a..1cc68ca2fe 100644
--- a/src/common/rendering/hwrenderer/data/hw_bonebuffer.cpp
+++ b/src/common/rendering/hwrenderer/data/hw_bonebuffer.cpp
@@ -103,8 +103,11 @@ int BoneBuffer::UploadBones(const TArray<VSMatrix>& bones)
 
 int BoneBuffer::GetBinding(unsigned int index, size_t* pOffset, size_t* pSize)
 {
+	unsigned int offset = index;
+
 	// this function will only get called if a uniform buffer is used. For a shader storage buffer we only need to bind the buffer once at the start.
-	unsigned int offset = (index / mBlockAlign) * mBlockAlign;
+	if (mBlockAlign > 0)
+		offset = (index / mBlockAlign) * mBlockAlign;
 
 	*pOffset = offset * BONE_SIZE;
 	*pSize = mBlockSize * BONE_SIZE;
diff --git a/wadsrc/static/shaders/glsl/main.vp b/wadsrc/static/shaders/glsl/main.vp
index e41152065c..d9ab20fa37 100644
--- a/wadsrc/static/shaders/glsl/main.vp
+++ b/wadsrc/static/shaders/glsl/main.vp
@@ -169,7 +169,7 @@ void AddWeightedBone(uint boneIndex, float weight, inout vec4 position, inout ve
 {
 	if (weight != 0.0)
 	{
-		mat4 transform = bones[uBoneIndexBase + boneIndex];
+		mat4 transform = bones[uBoneIndexBase + (int)boneIndex];
 		mat3 rotation = mat3(transform);
 		position += (transform * aPosition) * weight;
 		normal += (rotation * aNormal.xyz) * weight;