diff --git a/src/ambiguities.jl b/src/ambiguities.jl
index 24a1def0..782c43f2 100644
--- a/src/ambiguities.jl
+++ b/src/ambiguities.jl
@@ -12,7 +12,7 @@ false-positive.
 - `color::Union{Bool, Nothing} = nothing`: Enable/disable colorful
   output if a `Bool`.  `nothing` (default) means to inherit the
   setting in the current process.
-- `exclude::AbstractArray = []`: A vector of functions or types to be
+- `exclude::AbstractVector = []`: A vector of functions or types to be
   excluded from ambiguity testing.  A function means to exclude _all_
   its methods.  A type means to exclude _all_ its methods of the
   callable (sometimes also called "functor").  That is to say,
@@ -92,7 +92,7 @@ end
 function _test_ambiguities(
     packages::Vector{PkgId};
     color::Union{Bool,Nothing} = nothing,
-    exclude::AbstractArray = [],
+    exclude::AbstractVector = [],
     broken::Bool = false,
     # Options to be passed to `Test.detect_ambiguities`:
     detect_ambiguities_options...,
diff --git a/src/stale_deps.jl b/src/stale_deps.jl
index 73c45699..991a6e56 100644
--- a/src/stale_deps.jl
+++ b/src/stale_deps.jl
@@ -27,7 +27,7 @@ end
 analyze_stale_deps(packages, kwargs...) =
     [_analyze_stale_deps_1(pkg; kwargs...) for pkg in aspkgids(packages)]
 
-function _analyze_stale_deps_1(pkg::PkgId; ignore::AbstractArray{Symbol} = Symbol[])
+function _analyze_stale_deps_1(pkg::PkgId; ignore::AbstractVector{Symbol} = Symbol[])
     label = "$pkg"
 
     result = root_project_or_failed_lazytest(pkg)
@@ -69,9 +69,9 @@ end
 # Side-effect -free part of stale dependency analysis.
 function _analyze_stale_deps_2(;
     pkg::PkgId,
-    deps::AbstractArray{PkgId},
-    loaded_uuids::AbstractArray{UUID},
-    ignore::AbstractArray{Symbol},
+    deps::AbstractVector{PkgId},
+    loaded_uuids::AbstractVector{UUID},
+    ignore::AbstractVector{Symbol},
 )
     label = "$pkg"
     deps_uuids = [p.uuid for p in deps]