diff --git a/tgt-vhdl/scope.cc b/tgt-vhdl/scope.cc
index a5ca5d6ff..79a1e0ce2 100644
--- a/tgt-vhdl/scope.cc
+++ b/tgt-vhdl/scope.cc
@@ -425,6 +425,11 @@ int draw_function(ivl_scope_t scope, ivl_scope_t parent)
       remember_signal(sig, func->get_scope());
       rename_signal(sig, signame);
    }
+
+   // Non-blocking assignment not allowed in functions
+   func->get_scope()->set_allow_signal_assignment(false);
+   
+   draw_stmt(func, func->get_container(), ivl_scope_def(scope));
    
    assert(func); 
    ent->get_arch()->get_scope()->add_decl(func);   
diff --git a/tgt-vhdl/stmt.cc b/tgt-vhdl/stmt.cc
index 59166026d..c3bcaa183 100644
--- a/tgt-vhdl/stmt.cc
+++ b/tgt-vhdl/stmt.cc
@@ -116,6 +116,8 @@ static int draw_nbassign(vhdl_procedural *proc, stmt_container *container,
       return 1;
    }
 
+   assert(proc->get_scope()->allow_signal_assignment());
+
    ivl_lval_t lval = ivl_stmt_lval(stmt, 0);
    ivl_signal_t sig;
    if ((sig = ivl_lval_sig(lval))) {
@@ -201,21 +203,27 @@ static int draw_assign(vhdl_procedural *proc, stmt_container *container,
 
          decl->set_initial(rhs);
 
-         // This signal may be used e.g. in a loop test so we need
-         // to make a variable as well
-         blocking_assign_to(proc, sig);
-
-         // The signal may have been renamed by the above call
-         const std::string &renamed = get_renamed_signal(sig);
+         if (proc->get_scope()->allow_signal_assignment()) {
+            // This signal may be used e.g. in a loop test so we need
+            // to make a variable as well
+            blocking_assign_to(proc, sig);
+            
+            // The signal may have been renamed by the above call
+            const std::string &renamed = get_renamed_signal(sig);
          
-         vhdl_var_ref *lval_ref = new vhdl_var_ref(renamed.c_str(), NULL);
-         vhdl_var_ref *sig_ref = new vhdl_var_ref(signame.c_str(), NULL);
-         
-         vhdl_assign_stmt *assign = new vhdl_assign_stmt(lval_ref, sig_ref);
-         container->add_stmt(assign);
+            vhdl_var_ref *lval_ref = new vhdl_var_ref(renamed.c_str(), NULL);
+            vhdl_var_ref *sig_ref = new vhdl_var_ref(signame.c_str(), NULL);
+            
+            vhdl_assign_stmt *assign = new vhdl_assign_stmt(lval_ref, sig_ref);
+            container->add_stmt(assign);
+         }
       }
       else {
-         blocking_assign_to(proc, sig);
+         if (proc->get_scope()->allow_signal_assignment()) {
+            // Remember we need to write the variable back to the
+            // original signal
+            blocking_assign_to(proc, sig);
+         }
 
          // The signal may have been renamed by the above call
          const std::string &renamed = get_renamed_signal(sig);
diff --git a/tgt-vhdl/vhdl_syntax.cc b/tgt-vhdl/vhdl_syntax.cc
index 97fbc2753..87629a46f 100644
--- a/tgt-vhdl/vhdl_syntax.cc
+++ b/tgt-vhdl/vhdl_syntax.cc
@@ -26,7 +26,7 @@
 #include <typeinfo>
 
 vhdl_scope::vhdl_scope()
-   : parent_(NULL), init_(false)
+   : parent_(NULL), init_(false), sig_assign_(true)
 {
 
 }
diff --git a/tgt-vhdl/vhdl_syntax.hh b/tgt-vhdl/vhdl_syntax.hh
index 463a637b4..a356cb7b9 100644
--- a/tgt-vhdl/vhdl_syntax.hh
+++ b/tgt-vhdl/vhdl_syntax.hh
@@ -547,10 +547,13 @@ public:
 
    bool initializing() const { return init_; }
    void set_initializing(bool i) { init_ = i; }
+
+   void set_allow_signal_assignment(bool b) { sig_assign_ = b; }
+   bool allow_signal_assignment() const { return sig_assign_; }
 private:
    decl_list_t decls_;
    vhdl_scope *parent_;
-   bool init_;
+   bool init_, sig_assign_;
 };