diff --git a/include/clasp/clbind/inheritance.fwd.h b/include/clasp/clbind/inheritance.fwd.h
index fe381df044..13dfd7ace8 100644
--- a/include/clasp/clbind/inheritance.fwd.h
+++ b/include/clasp/clbind/inheritance.fwd.h
@@ -6,7 +6,8 @@ namespace detail {
 
 typedef void *(*cast_function)(void *);
 
-struct edge {
+class edge {
+public:
   edge(class_id target, cast_function cast)
       : target(target), cast(cast) {}
   edge() {};
@@ -18,7 +19,8 @@ inline bool operator<(edge const &x, edge const &y) {
   return x.target < y.target;
 }
 
-struct vertex {
+class vertex {
+public:
   vertex(class_id id)
     : id(id) {}
 
diff --git a/include/clasp/core/commandLineOptions.h b/include/clasp/core/commandLineOptions.h
index e66ade1761..ce3431f014 100644
--- a/include/clasp/core/commandLineOptions.h
+++ b/include/clasp/core/commandLineOptions.h
@@ -29,7 +29,7 @@ THE SOFTWARE.
 
 namespace core {
 
-class CommandLineOptions;
+struct CommandLineOptions;
 
 typedef void (*process_arguments_callback)(CommandLineOptions *);
 
diff --git a/include/clasp/core/core.h b/include/clasp/core/core.h
index 8c3ddca70d..e3eb2f52a7 100644
--- a/include/clasp/core/core.h
+++ b/include/clasp/core/core.h
@@ -813,7 +813,7 @@ typedef gctools::smart_ptr<SymbolToEnumConverter_O> SymbolToEnumConverter_sp;
 } // namespace core
 
 namespace gctools {
-class Layout_code;
+struct Layout_code;
 // Defined in clasp/src/gctools/gc_interface.cc
 extern Layout_code *get_stamp_layout_codes();
 }; // namespace gctools
diff --git a/include/clasp/core/hashTable.h b/include/clasp/core/hashTable.h
index d2d14daa6a..c412cb28b3 100644
--- a/include/clasp/core/hashTable.h
+++ b/include/clasp/core/hashTable.h
@@ -48,10 +48,11 @@ size_t next_hash_table_id();
 
 namespace core{
 
-struct KeyValuePair {
-  KeyValuePair(T_sp k, T_sp v) : _Key(k), _Value(v) {};
+class KeyValuePair {
+public:
   core::T_sp _Key;
   core::T_sp _Value;
+  KeyValuePair(T_sp k, T_sp v) : _Key(k), _Value(v) {};
 };
 
   FORWARD(HashTable);
diff --git a/include/clasp/core/lisp.h b/include/clasp/core/lisp.h
index 800900725e..fb7708c9ea 100644
--- a/include/clasp/core/lisp.h
+++ b/include/clasp/core/lisp.h
@@ -865,12 +865,9 @@ struct SafeBufferStr8Ns {
 
 void initializeLisp();
 
-class LispHolder //: public gctools::StackRoot
-    {
-private:
+struct LispHolder //: public gctools::StackRoot
+{
   LispPtr lisp_;
-
-public:
   /*! Pass the mpiProcess rank in (rank) or set to 0 if there is only one process */
   LispHolder(bool mpiEnabled, int mpiRank, int mpiSize);
 
diff --git a/include/clasp/gctools/memoryManagement.h b/include/clasp/gctools/memoryManagement.h
index c07257b2e1..53c802d72e 100644
--- a/include/clasp/gctools/memoryManagement.h
+++ b/include/clasp/gctools/memoryManagement.h
@@ -1036,15 +1036,15 @@ extern size_t global_sizeof_fwd;
 inline size_t Align(size_t size) { return ((AlignUp(size) >= global_sizeof_fwd) ? AlignUp(size) : global_sizeof_fwd); };
 
 // Manually define these for the sake of As<Fixnum_sp> etc.
-template <> class gctools::GCStamp<core::Fixnum_I> {
+template <> struct gctools::GCStamp<core::Fixnum_I> {
 public:
   static GCStampEnum const StampWtag = STAMPWTAG_core__Fixnum_dummy_O;
 };
-template <> class gctools::GCStamp<core::SingleFloat_I> {
+template <> struct gctools::GCStamp<core::SingleFloat_I> {
 public:
   static GCStampEnum const StampWtag = STAMPWTAG_core__SingleFloat_dummy_O;
 };
-template <> class gctools::GCStamp<core::Character_I> {
+template <> struct gctools::GCStamp<core::Character_I> {
 public:
   static GCStampEnum const StampWtag = STAMPWTAG_core__Character_dummy_O;
 };
diff --git a/include/clasp/gctools/pointer_tagging.h b/include/clasp/gctools/pointer_tagging.h
index dd964b0692..bae9feb407 100644
--- a/include/clasp/gctools/pointer_tagging.h
+++ b/include/clasp/gctools/pointer_tagging.h
@@ -61,7 +61,7 @@ typedef int32_t integer32_t;
 typedef int64_t integer64_t;
 
 namespace core {
-  class Vaslist;
+  struct Vaslist;
   class Code_S;
 };