diff --git a/base/loading.jl b/base/loading.jl
index d49c8aa91e3b7..ee6c47c7ce155 100644
--- a/base/loading.jl
+++ b/base/loading.jl
@@ -1388,13 +1388,12 @@ function insert_extension_triggers(env::String, pkg::PkgId)::Union{Nothing,Missi
         proj_pkg = project_file_name_uuid(implicit_project_file, pkg.name)
         if pkg == proj_pkg
             d_proj = parsed_toml(implicit_project_file)
-            weakdeps = get(d_proj, "weakdeps", nothing)::Union{Nothing, Vector{String}, Dict{String,Any}}
             extensions = get(d_proj, "extensions", nothing)::Union{Nothing, Dict{String, Any}}
             extensions === nothing && return
-            weakdeps === nothing && return
-            if weakdeps isa Dict{String, Any}
-                return _insert_extension_triggers(pkg, extensions, weakdeps)
-            end
+            weakdeps = get(Dict{String, Any}, d_proj, "weakdeps")::Dict{String,Any}
+            deps = get(Dict{String, Any}, d_proj, "deps")::Dict{String,Any}
+            total_deps = merge(weakdeps, deps)
+            return _insert_extension_triggers(pkg, extensions, total_deps)
         end
 
         # Now look in manifest
@@ -1409,27 +1408,35 @@ function insert_extension_triggers(env::String, pkg::PkgId)::Union{Nothing,Missi
                 uuid = get(entry, "uuid", nothing)::Union{String, Nothing}
                 uuid === nothing && continue
                 if UUID(uuid) == pkg.uuid
-                    weakdeps = get(entry, "weakdeps", nothing)::Union{Nothing, Vector{String}, Dict{String,Any}}
                     extensions = get(entry, "extensions", nothing)::Union{Nothing, Dict{String, Any}}
                     extensions === nothing && return
-                    weakdeps === nothing && return
-                    if weakdeps isa Dict{String, Any}
-                        return _insert_extension_triggers(pkg, extensions, weakdeps)
+                    weakdeps = get(Dict{String, Any}, entry, "weakdeps")::Union{Vector{String}, Dict{String,Any}}
+                    deps = get(Dict{String, Any}, entry, "deps")::Union{Vector{String}, Dict{String,Any}}
+
+                    function expand_deps_list(deps′::Vector{String})
+                        deps′_expanded = Dict{String, Any}()
+                        for (dep_name, entries) in d
+                            dep_name in deps′ || continue
+                            entries::Vector{Any}
+                            if length(entries) != 1
+                                error("expected a single entry for $(repr(dep_name)) in $(repr(project_file))")
+                            end
+                            entry = first(entries)::Dict{String, Any}
+                            uuid = entry["uuid"]::String
+                            deps′_expanded[dep_name] = uuid
+                        end
+                        return deps′_expanded
                     end
 
-                    d_weakdeps = Dict{String, Any}()
-                    for (dep_name, entries) in d
-                        dep_name in weakdeps || continue
-                        entries::Vector{Any}
-                        if length(entries) != 1
-                            error("expected a single entry for $(repr(dep_name)) in $(repr(project_file))")
-                        end
-                        entry = first(entries)::Dict{String, Any}
-                        uuid = entry["uuid"]::String
-                        d_weakdeps[dep_name] = uuid
+                    if weakdeps isa Vector{String}
+                        weakdeps = expand_deps_list(weakdeps)
+                    end
+                    if deps isa Vector{String}
+                        deps = expand_deps_list(deps)
                     end
-                    @assert length(d_weakdeps) == length(weakdeps)
-                    return _insert_extension_triggers(pkg, extensions, d_weakdeps)
+
+                    total_deps = merge(weakdeps, deps)
+                    return _insert_extension_triggers(pkg, extensions, total_deps)
                 end
             end
         end
@@ -1437,7 +1444,7 @@ function insert_extension_triggers(env::String, pkg::PkgId)::Union{Nothing,Missi
     return nothing
 end
 
-function _insert_extension_triggers(parent::PkgId, extensions::Dict{String, Any}, weakdeps::Dict{String, Any})
+function _insert_extension_triggers(parent::PkgId, extensions::Dict{String, Any}, totaldeps::Dict{String, Any})
     for (ext, triggers) in extensions
         triggers = triggers::Union{String, Vector{String}}
         triggers isa String && (triggers = [triggers])
@@ -1451,7 +1458,7 @@ function _insert_extension_triggers(parent::PkgId, extensions::Dict{String, Any}
         push!(trigger1, gid)
         for trigger in triggers
             # TODO: Better error message if this lookup fails?
-            uuid_trigger = UUID(weakdeps[trigger]::String)
+            uuid_trigger = UUID(totaldeps[trigger]::String)
             trigger_id = PkgId(uuid_trigger, trigger)
             if !haskey(explicit_loaded_modules, trigger_id) || haskey(package_locks, trigger_id)
                 trigger1 = get!(Vector{ExtensionId}, EXT_DORMITORY, trigger_id)
diff --git a/base/precompilation.jl b/base/precompilation.jl
index 8185fe8e8230b..9acbd2a11f202 100644
--- a/base/precompilation.jl
+++ b/base/precompilation.jl
@@ -409,7 +409,7 @@ function precompilepkgs(pkgs::Vector{String}=String[];
             all_extdeps_available = true
             for extdep_uuid in extdep_uuids
                 extdep_name = env.names[extdep_uuid]
-                if extdep_uuid in keys(env.deps) || Base.in_sysimage(Base.PkgId(extdep_uuid, extdep_name))
+                if extdep_uuid in keys(env.deps)
                     push!(ext_deps, Base.PkgId(extdep_uuid, extdep_name))
                 else
                     all_extdeps_available = false
diff --git a/doc/src/manual/code-loading.md b/doc/src/manual/code-loading.md
index 35d88ed13bc89..5c8315693c71e 100644
--- a/doc/src/manual/code-loading.md
+++ b/doc/src/manual/code-loading.md
@@ -351,7 +351,7 @@ Since the primary environment is typically the environment of a project you're w
 
 ### [Package Extensions](@id man-extensions)
 
-A package "extension" is a module that is automatically loaded when a specified set of other packages (its "extension dependencies") are loaded in the current Julia session. Extensions are defined under the `[extensions]` section in the project file. The extension dependencies of an extension are a subset of those packages listed under the `[weakdeps]` section of the project file. Those packages can have compat entries like other packages.
+A package "extension" is a module that is automatically loaded when a specified set of other packages (its "triggers") are loaded in the current Julia session. Extensions are defined under the `[extensions]` section in the project file. The triggers of an extension are a subset of those packages listed under the `[weakdeps]` (and possibly, but uncommonly the `[deps]`) section of the project file. Those packages can have compat entries like other packages.
 
 ```toml
 name = "MyPackage"
@@ -371,8 +371,8 @@ FooExt = "ExtDep"
 ```
 
 The keys under `extensions` are the names of the extensions.
-They are loaded when all the packages on the right hand side (the extension dependencies) of that extension are loaded.
-If an extension only has one extension dependency the list of extension dependencies can be written as just a string for brevity.
+They are loaded when all the packages on the right hand side (the triggers) of that extension are loaded.
+If an extension only has one trigger the list of triggers can be written as just a string for brevity.
 The location for the entry point of the extension is either in `ext/FooExt.jl` or `ext/FooExt/FooExt.jl` for
 extension `FooExt`.
 The content of an extension is often structured as:
@@ -380,10 +380,10 @@ The content of an extension is often structured as:
 ```
 module FooExt
 
-# Load main package and extension dependencies
+# Load main package and triggers
 using MyPackage, ExtDep
 
-# Extend functionality in main package with types from the extension dependencies
+# Extend functionality in main package with types from the triggers
 MyPackage.func(x::ExtDep.SomeStruct) = ...
 
 end
@@ -391,7 +391,7 @@ end
 
 When a package with extensions is added to an environment, the `weakdeps` and `extensions` sections
 are stored in the manifest file in the section for that package. The dependency lookup rules for
-a package are the same as for its "parent" except that the listed extension dependencies are also considered as
+a package are the same as for its "parent" except that the listed triggers are also considered as
 dependencies.
 
 ### [Workspaces](@id workspaces)
diff --git a/test/loading.jl b/test/loading.jl
index 182db7c4a6d15..4cd0cb7dac823 100644
--- a/test/loading.jl
+++ b/test/loading.jl
@@ -1057,7 +1057,9 @@ end
                 $ew HasDepWithExtensions.do_something() || error("do_something errored")
                 using ExtDep2
                 $ew using ExtDep2
-                $ew HasExtensions.ext_folder_loaded || error("ext_folder_loaded not set")
+                using ExtDep3
+                $ew using ExtDep3
+                $ew HasExtensions.ext_dep_loaded || error("ext_dep_loaded not set")
             end
             """
             return `$(Base.julia_cmd()) $compile --startup-file=no -e $cmd`
@@ -1105,6 +1107,8 @@ end
             Base.get_extension(HasExtensions, :Extension) isa Module || error("expected extension to load")
             using ExtDep2
             Base.get_extension(HasExtensions, :ExtensionFolder) isa Module || error("expected extension to load")
+            using ExtDep3
+            Base.get_extension(HasExtensions, :ExtensionDep) isa Module || error("expected extension to load")
         end
         """
         for compile in (`--compiled-modules=no`, ``)
diff --git a/test/project/Extensions/EnvWithHasExtensions/Manifest.toml b/test/project/Extensions/EnvWithHasExtensions/Manifest.toml
index 8ac961fa1a9a9..004ef7892c173 100644
--- a/test/project/Extensions/EnvWithHasExtensions/Manifest.toml
+++ b/test/project/Extensions/EnvWithHasExtensions/Manifest.toml
@@ -1,8 +1,8 @@
 # This file is machine-generated - editing it directly is not advised
 
-julia_version = "1.9.0-beta4"
+julia_version = "1.12.0-DEV"
 manifest_format = "2.0"
-project_hash = "caa716752e6dff3d77c3de929ebbb5d2024d04ef"
+project_hash = "a4c480cfa7da9610333d5c42623bf746bd286c5f"
 
 [[deps.ExtDep]]
 deps = ["SomePackage"]
@@ -18,10 +18,12 @@ version = "0.1.0"
     [deps.HasExtensions.extensions]
     Extension = "ExtDep"
     ExtensionFolder = ["ExtDep", "ExtDep2"]
+    LinearAlgebraExt = "LinearAlgebra"
 
     [deps.HasExtensions.weakdeps]
     ExtDep = "fa069be4-f60b-4d4c-8b95-f8008775090c"
     ExtDep2 = "55982ee5-2ad5-4c40-8cfe-5e9e1b01500d"
+    LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 
 [[deps.SomePackage]]
 path = "../SomePackage"
diff --git a/test/project/Extensions/ExtDep3.jl/Project.toml b/test/project/Extensions/ExtDep3.jl/Project.toml
new file mode 100644
index 0000000000000..690b2f1cffff4
--- /dev/null
+++ b/test/project/Extensions/ExtDep3.jl/Project.toml
@@ -0,0 +1,4 @@
+name = "ExtDep3"
+uuid = "a5541f1e-a556-4fdc-af15-097880d743a1"
+version = "0.1.0"
+authors = ["Kristoffer <kcarlsson89@gmail.com>"]
diff --git a/test/project/Extensions/ExtDep3.jl/src/ExtDep3.jl b/test/project/Extensions/ExtDep3.jl/src/ExtDep3.jl
new file mode 100644
index 0000000000000..96a0b472d06c5
--- /dev/null
+++ b/test/project/Extensions/ExtDep3.jl/src/ExtDep3.jl
@@ -0,0 +1,5 @@
+module ExtDep3
+
+greet() = print("Hello World!")
+
+end # module ExtDep3
diff --git a/test/project/Extensions/HasDepWithExtensions.jl/Manifest.toml b/test/project/Extensions/HasDepWithExtensions.jl/Manifest.toml
index 15f068f250ce3..5706aba59d1e0 100644
--- a/test/project/Extensions/HasDepWithExtensions.jl/Manifest.toml
+++ b/test/project/Extensions/HasDepWithExtensions.jl/Manifest.toml
@@ -1,8 +1,8 @@
 # This file is machine-generated - editing it directly is not advised
 
-julia_version = "1.10.0"
+julia_version = "1.12.0-DEV"
 manifest_format = "2.0"
-project_hash = "d523b3401f72a1ed34b7b43749fd2655c6b78542"
+project_hash = "4e196b07f2ee7adc48ac9d528d42b3cf3737c7a0"
 
 [[deps.ExtDep]]
 deps = ["SomePackage"]
@@ -15,13 +15,20 @@ path = "../ExtDep2"
 uuid = "55982ee5-2ad5-4c40-8cfe-5e9e1b01500d"
 version = "0.1.0"
 
+[[deps.ExtDep3]]
+path = "../ExtDep3.jl"
+uuid = "a5541f1e-a556-4fdc-af15-097880d743a1"
+version = "0.1.0"
+
 [[deps.HasExtensions]]
+deps = ["ExtDep3"]
 path = "../HasExtensions.jl"
 uuid = "4d3288b3-3afc-4bb6-85f3-489fffe514c8"
 version = "0.1.0"
 
     [deps.HasExtensions.extensions]
     Extension = "ExtDep"
+    ExtensionDep = "ExtDep3"
     ExtensionFolder = ["ExtDep", "ExtDep2"]
     LinearAlgebraExt = "LinearAlgebra"
 
diff --git a/test/project/Extensions/HasDepWithExtensions.jl/Project.toml b/test/project/Extensions/HasDepWithExtensions.jl/Project.toml
index 8f308a9fbee72..aa4956caada74 100644
--- a/test/project/Extensions/HasDepWithExtensions.jl/Project.toml
+++ b/test/project/Extensions/HasDepWithExtensions.jl/Project.toml
@@ -5,4 +5,5 @@ version = "0.1.0"
 [deps]
 ExtDep = "fa069be4-f60b-4d4c-8b95-f8008775090c"
 ExtDep2 = "55982ee5-2ad5-4c40-8cfe-5e9e1b01500d"
+ExtDep3 = "a5541f1e-a556-4fdc-af15-097880d743a1"
 HasExtensions = "4d3288b3-3afc-4bb6-85f3-489fffe514c8"
diff --git a/test/project/Extensions/HasExtensions.jl/Manifest.toml b/test/project/Extensions/HasExtensions.jl/Manifest.toml
index 55f7958701a75..429c6598fc4f4 100644
--- a/test/project/Extensions/HasExtensions.jl/Manifest.toml
+++ b/test/project/Extensions/HasExtensions.jl/Manifest.toml
@@ -1,7 +1,10 @@
 # This file is machine-generated - editing it directly is not advised
 
-julia_version = "1.10.0-DEV"
+julia_version = "1.12.0-DEV"
 manifest_format = "2.0"
-project_hash = "c87947f1f1f070eea848950c304d668a112dec3d"
+project_hash = "c0bb526b75939a74a6195ee4819e598918a22ad7"
 
-[deps]
+[[deps.ExtDep3]]
+path = "../ExtDep3.jl"
+uuid = "a5541f1e-a556-4fdc-af15-097880d743a1"
+version = "0.1.0"
diff --git a/test/project/Extensions/HasExtensions.jl/Project.toml b/test/project/Extensions/HasExtensions.jl/Project.toml
index a5f9bb1e42d29..fe21a1423f543 100644
--- a/test/project/Extensions/HasExtensions.jl/Project.toml
+++ b/test/project/Extensions/HasExtensions.jl/Project.toml
@@ -2,6 +2,9 @@ name = "HasExtensions"
 uuid = "4d3288b3-3afc-4bb6-85f3-489fffe514c8"
 version = "0.1.0"
 
+[deps]
+ExtDep3 = "a5541f1e-a556-4fdc-af15-097880d743a1"
+
 [weakdeps]
 ExtDep = "fa069be4-f60b-4d4c-8b95-f8008775090c"
 ExtDep2 = "55982ee5-2ad5-4c40-8cfe-5e9e1b01500d"
@@ -9,5 +12,6 @@ LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 
 [extensions]
 Extension = "ExtDep"
+ExtensionDep = "ExtDep3"
 ExtensionFolder = ["ExtDep", "ExtDep2"]
 LinearAlgebraExt = "LinearAlgebra"
diff --git a/test/project/Extensions/HasExtensions.jl/ext/ExtensionDep.jl b/test/project/Extensions/HasExtensions.jl/ext/ExtensionDep.jl
new file mode 100644
index 0000000000000..e2710d4d89bbb
--- /dev/null
+++ b/test/project/Extensions/HasExtensions.jl/ext/ExtensionDep.jl
@@ -0,0 +1,9 @@
+module ExtensionDep
+
+using HasExtensions, ExtDep3
+
+function __init__()
+    HasExtensions.ext_dep_loaded = true
+end
+
+end
diff --git a/test/project/Extensions/HasExtensions.jl/src/HasExtensions.jl b/test/project/Extensions/HasExtensions.jl/src/HasExtensions.jl
index dbfaeec4f8812..9d9785f87f790 100644
--- a/test/project/Extensions/HasExtensions.jl/src/HasExtensions.jl
+++ b/test/project/Extensions/HasExtensions.jl/src/HasExtensions.jl
@@ -6,5 +6,6 @@ foo(::HasExtensionsStruct) = 1
 
 ext_loaded = false
 ext_folder_loaded = false
+ext_dep_loaded = false
 
 end # module