diff --git a/ethosu/regor/tosa/tosa_reader.cpp b/ethosu/regor/tosa/tosa_reader.cpp
index 3e403482ab8c6c3f4e404802a0f98a9a4d7f1d8f..4c15079dbbe9e4747de4f8f23d974265fd28a6e2 100644
--- a/ethosu/regor/tosa/tosa_reader.cpp
+++ b/ethosu/regor/tosa/tosa_reader.cpp
@@ -372,7 +372,13 @@ void TosaReader::LoadGraphs(const tosaFb::TosaGraph *model, std::list<GraphBuild
             // Vector to API shape
             auto ToApiShape = [](const ::flatbuffers::Vector<int32_t> *in) -> GraphApi::GraphShape
             {
-                GraphApi::GraphShape out;
+                GraphApi::GraphShape out{};
+                // Interpret a missing shape vector as scalar, rank 0 shape.
+                if ( in == nullptr )
+                {
+                    out.count = 0;
+                    return out;
+                }
                 const auto &buf = SafeDeref(in, "No shape vector");
                 tosa_assert(buf.size() <= std::size(out.axisNHWC), "Shape rank exceeds maximum allowed");
                 for ( int i = 0; i < int(buf.size()); i++ )