diff --git a/src/interface.jl b/src/interface.jl
index 95b77f3..287252f 100644
--- a/src/interface.jl
+++ b/src/interface.jl
@@ -484,7 +484,7 @@ function run_lint(
 
         # We are now reaching a bug HERE
         if isnothing(r)
-            @error "BUG FOUND IN StaticLint.jl, message from hint $(m) cannot be extracted"
+            @error "BUG FOUND IN StaticLint.jl, message from hint: $(m) cannot be extracted"
             return "ERROR"
         end
 
diff --git a/src/linting/extended_checks.jl b/src/linting/extended_checks.jl
index c7273b6..97647e4 100644
--- a/src/linting/extended_checks.jl
+++ b/src/linting/extended_checks.jl
@@ -212,6 +212,7 @@ struct RelPathAPIUsage_Extension <: ViolationExtendedRule end
 struct NonFrontShapeAPIUsage_Extension <: ViolationExtendedRule end
 struct InterpolationInSafeLog_Extension <: RecommendationExtendedRule end
 struct UseOfStaticThreads <: ViolationExtendedRule end
+struct ReturnTypeInDerived <: ViolationExtendedRule end
 
 
 const all_extended_rule_types = Ref{Any}(
@@ -574,4 +575,10 @@ function check(t::UseOfStaticThreads, x::EXPR)
     msg = "Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`. Static threads must not be used as generated tasks will not be able to migrate across threads."
     generic_check(t, x, "@threads :static hole_variable_star", msg)
     generic_check(t, x, "Threads.@threads :static hole_variable_star", msg)
+end
+
+function check(t::ReturnTypeInDerived, x::EXPR, markers::Dict{Symbol,String})
+    msg = "Return type necessary in `@derived` functions."
+    generic_check(t, x, "@derived hole_variable function hole_variable(hole_variable_star) hole_variable_star end", msg)
+    generic_check(t, x, "@derived function hole_variable(hole_variable_star) hole_variable_star end", msg)
 end
\ No newline at end of file
diff --git a/test/rai_rules_tests.jl b/test/rai_rules_tests.jl
index 6597cc1..cb990d7 100644
--- a/test/rai_rules_tests.jl
+++ b/test/rai_rules_tests.jl
@@ -1988,3 +1988,50 @@ end
     @test lint_test(source, "Line 2, column 5: Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`.")
     @test lint_test(source, "Line 6, column 5: Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`.")
 end
+
+@testset "Return type in derived functions" begin
+    @testset "No error" begin
+        source = """
+            @derived v=10 function PhaseAPI.generated_defs_for_id(
+                rt::Runtime,
+                path::RelPath,
+                phase::PhaseNormalization,
+            )::PhaseResult
+
+                return nothing
+            end
+            """
+        @test !lint_has_error_test(source)
+        # @test lint_test(source, "Line 1, column 1: Return type necessary in `@derived` functions.")
+    end
+    @testset "With error 01" begin
+        source = """
+            @derived v=10 function PhaseAPI.generated_defs_for_id(
+                rt::Runtime,
+                path::RelPath,
+                phase::PhaseNormalization,
+            )
+
+                return nothing
+            end
+            """
+        @test lint_has_error_test(source)
+        @test lint_test(source, "Line 1, column 1: Return type necessary in `@derived` functions.")
+    end
+
+    @testset "With error 02" begin
+        source = """
+            @derived function PhaseAPI.generated_defs_for_id(
+                rt::Runtime,
+                path::RelPath,
+                phase::PhaseNormalization,
+            )
+
+                return nothing
+            end
+            """
+        @test lint_has_error_test(source)
+        @test lint_test(source, "Line 1, column 1: Return type necessary in `@derived` functions.")
+    end
+end
+