diff --git a/include/slang/ast/Compilation.h b/include/slang/ast/Compilation.h
index 88b329e7e..1c79c418f 100644
--- a/include/slang/ast/Compilation.h
+++ b/include/slang/ast/Compilation.h
@@ -739,7 +739,7 @@ class SLANG_EXPORT Compilation : public BumpAllocator {
 private:
     friend class Lookup;
     friend class Scope;
-    friend class DiagnosticVisitor;
+    friend struct DiagnosticVisitor;
 
     // Collected information about a resolved bind directive.
     struct ResolvedBind {
diff --git a/source/ast/symbols/BlockSymbols.cpp b/source/ast/symbols/BlockSymbols.cpp
index 88a311e1d..0c05a8ef1 100644
--- a/source/ast/symbols/BlockSymbols.cpp
+++ b/source/ast/symbols/BlockSymbols.cpp
@@ -191,6 +191,8 @@ StatementBlockSymbol& StatementBlockSymbol::fromSyntax(const Scope& scope,
     block->setAttributes(scope, syntax.attributes);
     block->blocks = Statement::createAndAddBlockItems(*block, *syntax.statement,
                                                       /* labelHandled */ false);
+
+    SLANG_ASSERT(curr && first);
     curr->addMember(*block);
 
     return *first;