diff --git a/stdlib/REPL/src/REPLCompletions.jl b/stdlib/REPL/src/REPLCompletions.jl
index 9c516581e9dae..59fcd29e4f7f3 100644
--- a/stdlib/REPL/src/REPLCompletions.jl
+++ b/stdlib/REPL/src/REPLCompletions.jl
@@ -576,7 +576,7 @@ end
 
 # lower `ex` and run type inference on the resulting top-level expression
 function repl_eval_ex(@nospecialize(ex), context_module::Module)
-    if isexpr(ex, :toplevel) || isexpr(ex, :tuple)
+    if (isexpr(ex, :toplevel) || isexpr(ex, :tuple)) && !isempty(ex.args)
         # get the inference result for the last expression
         ex = ex.args[end]
     end
diff --git a/stdlib/REPL/test/replcompletions.jl b/stdlib/REPL/test/replcompletions.jl
index d732d073fd6cc..58b29fccc66a6 100644
--- a/stdlib/REPL/test/replcompletions.jl
+++ b/stdlib/REPL/test/replcompletions.jl
@@ -1857,6 +1857,11 @@ let s = "@show some_issue36437.value.a; some_issue36437.value."
         @test n in c
     end
 end
+# https://github.com/JuliaLang/julia/issues/51505
+let s = "()."
+    c, r, res = test_complete_context(s)
+    @test res
+end
 
 # aggressive concrete evaluation on mutable allocation in `repl_frame`
 let s = "Ref(Issue36437(42))[]."