diff --git a/README.md b/README.md
index a6f2c6667c..fac9b1e8e5 100644
--- a/README.md
+++ b/README.md
@@ -7188,6 +7188,14 @@ interpolation buffer, one can specify vertex buffers
 (`RTC_BUFFER_TYPE_VERTEX`) and vertex attribute buffers
 (`RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE`) as well.
 
+The `bufferType` has to be either `RTC_BUFFER_TYPE_VERTEX` or
+`RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE`, and the `bufferSlot` has to be a
+valid slot of the specified buffer type, thus smaller than the number of
+time steps for vertex buffers and smaller than the vertex attribute
+count set using `rtcSetGeometryVertexAttributeCount` for vertex
+attribute buffers. Otherwise an `RTC_ERROR_INVALID_ARGUMENT` error is
+raised and no data is interpolated.
+
 The `rtcInterpolate` call stores `valueCount` number of interpolated
 floating point values to the memory location pointed to by `P`. One can
 avoid storing the interpolated value by setting `P` to `NULL`.
diff --git a/doc/src/api/rtcInterpolate.md b/doc/src/api/rtcInterpolate.md
index 5b581f5c69..e2fee6ebd9 100644
--- a/doc/src/api/rtcInterpolate.md
+++ b/doc/src/api/rtcInterpolate.md
@@ -51,6 +51,14 @@ interpolation buffer, one can specify vertex buffers
 (`RTC_BUFFER_TYPE_VERTEX`) and vertex attribute buffers
 (`RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE`) as well.
 
+The `bufferType` has to be either `RTC_BUFFER_TYPE_VERTEX` or
+`RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE`, and the `bufferSlot` has to be a
+valid slot of the specified buffer type, thus smaller than the number
+of time steps for vertex buffers and smaller than the vertex attribute
+count set using `rtcSetGeometryVertexAttributeCount` for vertex
+attribute buffers. Otherwise an `RTC_ERROR_INVALID_ARGUMENT` error is
+raised and no data is interpolated.
+
 The `rtcInterpolate` call stores `valueCount` number of interpolated
 floating point values to the memory location pointed to by `P`. One
 can avoid storing the interpolated value by setting `P` to `NULL`.
diff --git a/kernels/common/scene_curves.h b/kernels/common/scene_curves.h
index 7350a20ecd..68abf10a9e 100644
--- a/kernels/common/scene_curves.h
+++ b/kernels/common/scene_curves.h
@@ -545,16 +545,20 @@ namespace embree
       unsigned int valueCount = args->valueCount;
       
       /* calculate base pointer and stride */
-      assert((bufferType == RTC_BUFFER_TYPE_VERTEX && bufferSlot < numTimeSteps) ||
-             (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE && bufferSlot <= vertexAttribs.size()));
       const char* src = nullptr; 
       size_t stride = 0;
       if (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE) {
+        if (unlikely(bufferSlot >= vertexAttribs.size()))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex attribute buffer slot specified for interpolation");
         src    = vertexAttribs[bufferSlot].getPtr();
         stride = vertexAttribs[bufferSlot].getStride();
-      } else {
+      } else if (bufferType == RTC_BUFFER_TYPE_VERTEX) {
+        if (unlikely(bufferSlot >= numTimeSteps))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex buffer slot specified for interpolation");
         src    = vertices[bufferSlot].getPtr();
         stride = vertices[bufferSlot].getStride();
+      } else {
+        throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid buffer type specified for interpolation");
       }
 
       for (unsigned int i=0; i<valueCount; i+=N)
@@ -711,7 +715,8 @@ namespace embree
       /* we interpolate vertex attributes linearly for hermite basis */
       if (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE)
       {
-        assert(bufferSlot <= vertexAttribs.size());
+        if (unlikely(bufferSlot >= vertexAttribs.size()))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex attribute buffer slot specified for interpolation");
         const char* vsrc = vertexAttribs[bufferSlot].getPtr();
         const size_t vstride = vertexAttribs[bufferSlot].getStride();
         
@@ -730,9 +735,10 @@ namespace embree
       }
       
       /* interpolation for vertex buffers */
-      else
+      else if (bufferType == RTC_BUFFER_TYPE_VERTEX)
       {
-        assert(bufferSlot < numTimeSteps);
+        if (unlikely(bufferSlot >= numTimeSteps))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex buffer slot specified for interpolation");
         const char* vsrc = vertices[bufferSlot].getPtr();
         const char* tsrc = tangents[bufferSlot].getPtr();
         const size_t vstride = vertices[bufferSlot].getStride();
@@ -754,6 +760,8 @@ namespace embree
           if (ddPdudu) mem<vfloat<N>>::storeu(valid,ddPdudu+i,curve.eval_dudu(u));
         }
       }
+      else
+        throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid buffer type specified for interpolation");
     }
 
     void interpolate(const RTCInterpolateArguments* const args) {
diff --git a/kernels/common/scene_grid_mesh.h b/kernels/common/scene_grid_mesh.h
index cd374912f5..76f50522bb 100644
--- a/kernels/common/scene_grid_mesh.h
+++ b/kernels/common/scene_grid_mesh.h
@@ -86,16 +86,20 @@ namespace embree
       unsigned int valueCount = args->valueCount;
       
       /* calculate base pointer and stride */
-      assert((bufferType == RTC_BUFFER_TYPE_VERTEX && bufferSlot < numTimeSteps) ||
-             (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE && bufferSlot <= vertexAttribs.size()));
       const char* src = nullptr; 
       size_t stride = 0;
       if (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE) {
+        if (unlikely(bufferSlot >= vertexAttribs.size()))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex attribute buffer slot specified for interpolation");
         src    = vertexAttribs[bufferSlot].getPtr();
         stride = vertexAttribs[bufferSlot].getStride();
-      } else {
+      } else if (bufferType == RTC_BUFFER_TYPE_VERTEX) {
+        if (unlikely(bufferSlot >= numTimeSteps))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex buffer slot specified for interpolation");
         src    = vertices[bufferSlot].getPtr();
         stride = vertices[bufferSlot].getStride();
+      } else {
+        throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid buffer type specified for interpolation");
       }
       
       const Grid& grid = grids[primID];
diff --git a/kernels/common/scene_line_segments.h b/kernels/common/scene_line_segments.h
index a672abd8d2..f896628077 100644
--- a/kernels/common/scene_line_segments.h
+++ b/kernels/common/scene_line_segments.h
@@ -49,16 +49,20 @@ namespace embree
       unsigned int valueCount = args->valueCount;
       
       /* calculate base pointer and stride */
-      assert((bufferType == RTC_BUFFER_TYPE_VERTEX && bufferSlot < numTimeSteps) ||
-             (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE && bufferSlot <= vertexAttribs.size()));
       const char* src = nullptr;
       size_t stride = 0;
       if (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE) {
+        if (unlikely(bufferSlot >= vertexAttribs.size()))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex attribute buffer slot specified for interpolation");
         src    = vertexAttribs[bufferSlot].getPtr();
         stride = vertexAttribs[bufferSlot].getStride();
-      } else {
+      } else if (bufferType == RTC_BUFFER_TYPE_VERTEX) {
+        if (unlikely(bufferSlot >= numTimeSteps))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex buffer slot specified for interpolation");
         src    = vertices[bufferSlot].getPtr();
         stride = vertices[bufferSlot].getStride();
+      } else {
+        throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid buffer type specified for interpolation");
       }
       
       for (unsigned int i=0; i<valueCount; i+=N)
diff --git a/kernels/common/scene_quad_mesh.h b/kernels/common/scene_quad_mesh.h
index 646b08c1ab..60ea067f2f 100644
--- a/kernels/common/scene_quad_mesh.h
+++ b/kernels/common/scene_quad_mesh.h
@@ -68,16 +68,20 @@ namespace embree
       unsigned int valueCount = args->valueCount;
       
       /* calculate base pointer and stride */
-      assert((bufferType == RTC_BUFFER_TYPE_VERTEX && bufferSlot < numTimeSteps) ||
-             (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE && bufferSlot <= vertexAttribs.size()));
       const char* src = nullptr; 
       size_t stride = 0;
       if (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE) {
+        if (unlikely(bufferSlot >= vertexAttribs.size()))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex attribute buffer slot specified for interpolation");
         src    = vertexAttribs[bufferSlot].getPtr();
         stride = vertexAttribs[bufferSlot].getStride();
-      } else {
+      } else if (bufferType == RTC_BUFFER_TYPE_VERTEX) {
+        if (unlikely(bufferSlot >= numTimeSteps))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex buffer slot specified for interpolation");
         src    = vertices[bufferSlot].getPtr();
         stride = vertices[bufferSlot].getStride();
+      } else {
+        throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid buffer type specified for interpolation");
       }
       
       for (unsigned int i=0; i<valueCount; i+=N)
diff --git a/kernels/common/scene_subdiv_mesh.cpp b/kernels/common/scene_subdiv_mesh.cpp
index ebbf980d9b..4181c0ac8f 100644
--- a/kernels/common/scene_subdiv_mesh.cpp
+++ b/kernels/common/scene_subdiv_mesh.cpp
@@ -859,25 +859,27 @@ namespace embree
       unsigned int valueCount = args->valueCount;
       
       /* calculate base pointer and stride */
-      assert((bufferType == RTC_BUFFER_TYPE_VERTEX && bufferSlot < RTC_MAX_TIME_STEP_COUNT) ||
-             (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE && bufferSlot < RTC_MAX_USER_VERTEX_BUFFERS));
       const char* src = nullptr; 
       size_t stride = 0;
       std::vector<SharedLazyTessellationCache::CacheEntry>* baseEntry = nullptr;
       Topology* topo = nullptr;
       if (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE) {
-        assert(bufferSlot < vertexAttribs.size());
+        if (unlikely(bufferSlot >= vertexAttribs.size()))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex attribute buffer slot specified for interpolation");
         src    = vertexAttribs[bufferSlot].getPtr();
         stride = vertexAttribs[bufferSlot].getStride();
         baseEntry = &vertex_attrib_buffer_tags[bufferSlot];
         int topologyID = vertexAttribs[bufferSlot].userData;
         topo = &topology[topologyID];
-      } else {
-        assert(bufferSlot < numTimeSteps);
+      } else if (bufferType == RTC_BUFFER_TYPE_VERTEX) {
+        if (unlikely(bufferSlot >= numTimeSteps))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex buffer slot specified for interpolation");
         src    = vertices[bufferSlot].getPtr();
         stride = vertices[bufferSlot].getStride();
         baseEntry = &vertex_buffer_tags[bufferSlot];
         topo = &topology[0];
+      } else {
+        throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid buffer type specified for interpolation");
       }
       
       bool has_P = P;
@@ -936,25 +938,27 @@ namespace embree
       unsigned int valueCount = args->valueCount;
     
       /* calculate base pointer and stride */
-      assert((bufferType == RTC_BUFFER_TYPE_VERTEX && bufferSlot < RTC_MAX_TIME_STEP_COUNT) ||
-             (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE && bufferSlot < RTC_MAX_USER_VERTEX_BUFFERS));
       const char* src = nullptr; 
       size_t stride = 0;
       std::vector<SharedLazyTessellationCache::CacheEntry>* baseEntry = nullptr;
       Topology* topo = nullptr;
       if (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE) {
-        assert(bufferSlot < vertexAttribs.size());
+        if (unlikely(bufferSlot >= vertexAttribs.size()))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex attribute buffer slot specified for interpolation");
         src    = vertexAttribs[bufferSlot].getPtr();
         stride = vertexAttribs[bufferSlot].getStride();
         baseEntry = &vertex_attrib_buffer_tags[bufferSlot];
         int topologyID = vertexAttribs[bufferSlot].userData;
         topo = &topology[topologyID];
-      } else {
-        assert(bufferSlot < numTimeSteps);
+      } else if (bufferType == RTC_BUFFER_TYPE_VERTEX) {
+        if (unlikely(bufferSlot >= numTimeSteps))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex buffer slot specified for interpolation");
         src    = vertices[bufferSlot].getPtr();
         stride = vertices[bufferSlot].getStride();
         baseEntry = &vertex_buffer_tags[bufferSlot];
         topo = &topology[0];
+      } else {
+        throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid buffer type specified for interpolation");
       }
       
       const int* valid = (const int*) valid_i;
diff --git a/kernels/common/scene_triangle_mesh.h b/kernels/common/scene_triangle_mesh.h
index 3f014d85a2..533a41921c 100644
--- a/kernels/common/scene_triangle_mesh.h
+++ b/kernels/common/scene_triangle_mesh.h
@@ -62,16 +62,20 @@ namespace embree
       unsigned int valueCount = args->valueCount;
       
       /* calculate base pointer and stride */
-      assert((bufferType == RTC_BUFFER_TYPE_VERTEX && bufferSlot < numTimeSteps) ||
-             (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE && bufferSlot <= vertexAttribs.size()));
       const char* src = nullptr; 
       size_t stride = 0;
       if (bufferType == RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE) {
+        if (unlikely(bufferSlot >= vertexAttribs.size()))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex attribute buffer slot specified for interpolation");
         src    = vertexAttribs[bufferSlot].getPtr();
         stride = vertexAttribs[bufferSlot].getStride();
-      } else {
+      } else if (bufferType == RTC_BUFFER_TYPE_VERTEX) {
+        if (unlikely(bufferSlot >= numTimeSteps))
+          throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid vertex buffer slot specified for interpolation");
         src    = vertices[bufferSlot].getPtr();
         stride = vertices[bufferSlot].getStride();
+      } else {
+        throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"invalid buffer type specified for interpolation");
       }
       
       for (unsigned int i=0; i<valueCount; i+=N)