diff --git a/src/saving_files.jl b/src/saving_files.jl
index 8e1179c3..036d5500 100644
--- a/src/saving_files.jl
+++ b/src/saving_files.jl
@@ -137,10 +137,10 @@ function append_prefix_suffix(name, prefix, suffix)
             return prefix*'.'*suffix
         end
     end
-    if prefix != ""
+    if prefix != "" && !startswith(name, prefix)
         name = prefix*'_'*name
     end
-    if suffix != ""
+    if suffix != "" && !endswith(name, suffix)
         name *= '.'*suffix
     end
     return name
diff --git a/test/savefiles_tests.jl b/test/savefiles_tests.jl
index d3c4d649..4b0a5ec6 100644
--- a/test/savefiles_tests.jl
+++ b/test/savefiles_tests.jl
@@ -315,14 +315,18 @@ end
         x
         y
     end
+
     simulation = Dummy(1,2)
-    DrWatson.default_prefix(d::Dummy) = "Prefix_"
+    DrWatson.default_prefix(d::Dummy) = "Prefix"
 
-    sim, path = produce_or_load(f, simulation, "")
-    @test path == savename(simulation, "jld2")
-    
-    rm(path)
-    DrWatson.default_prefix(ntuple::NamedTuple) = ""
+    _, file = produce_or_load(f, simulation, path)
+    @test basename(file) == "Prefix_x=1_y=2.jld2"
+
+    filename = x -> savename(x; connector = " ")
+    _, file = produce_or_load(f, simulation, path; filename)
+    @test basename(file) == "Prefix x=1 y=2.jld2"
+
+    rm(path; recursive = true, force = true)
 end