diff --git a/src/registry_testing.jl b/src/registry_testing.jl
index d18936da..98565b63 100644
--- a/src/registry_testing.jl
+++ b/src/registry_testing.jl
@@ -262,7 +262,12 @@ end
 # Apply `_spacify_hyphens()` recursively through a dictionary
 function _spacify_hyphens(dict::Dict{K, V}) where {K, V}
     new_dict = Dict{K, V}()
-    for (k, v) in pairs(dict)
+    # Note: `Base.Dict` iterates key-value pairs, so it's sufficient for us to do
+    # `for (k, v) in dict`. However, there are some other dictionary implementations
+    # (such as the Dictionaries.jl package) that do not iterate key-value pairs. So,
+    # if we ever decide to widen the type signature of this method, we'll need to
+    # change `(k, v) in dict` to `(k, v) in pairs(dict)`.
+    for (k, v) in dict
         new_k = _spacify_hyphens(k)
         new_v = _spacify_hyphens(v)
     end