diff --git a/function.dd b/function.dd
index 9449056482..7fb79c03d5 100644
--- a/function.dd
+++ b/function.dd
@@ -5,6 +5,10 @@ $(SPEC_S Functions,
 $(GRAMMAR
 $(GNAME FuncDeclaration):
     $(GLINK2 declaration, StorageClasses)$(OPT) $(GLINK2 declaration, BasicType) $(GLINK FuncDeclarator) $(GLINK FunctionBody)
+    $(GLINK AutoFuncDeclaration)
+
+$(GNAME AutoFuncDeclaration):
+    $(GLINK2 declaration, StorageClasses) $(I Identifier) $(GLINK FuncDeclaratorSuffix) $(GLINK FunctionBody)
 
 $(GNAME FuncDeclarator):
     $(GLINK2 declaration, BasicType2)$(OPT) $(I Identifier) $(GLINK FuncDeclaratorSuffix)
diff --git a/grammar.dd b/grammar.dd
index 76817eed29..5b3248b0e2 100644
--- a/grammar.dd
+++ b/grammar.dd
@@ -1119,6 +1119,10 @@ $(H3 $(LNAME2 function, Function))
 $(GRAMMAR
 $(GNAME FuncDeclaration):
     $(GLINK StorageClasses)$(OPT) $(GLINK BasicType) $(GLINK FuncDeclarator) $(GLINK FunctionBody)
+    $(GLINK AutoFuncDeclaration)
+
+$(GNAME AutoFuncDeclaration):
+    $(GLINK StorageClasses) $(I Identifier) $(GLINK FuncDeclaratorSuffix) $(GLINK FunctionBody)
 
 $(GNAME FuncDeclarator):
     $(GLINK BasicType2)$(OPT) $(I Identifier) $(GLINK FuncDeclaratorSuffix)