diff --git a/src/tangent.jl b/src/tangent.jl
index a46dd031..75f5d258 100644
--- a/src/tangent.jl
+++ b/src/tangent.jl
@@ -90,9 +90,14 @@ struct ExplicitTangent{P <: Tuple} <: AbstractTangentSpace
     partials::P
 end
 
+
 @eval struct TaylorTangent{C <: Tuple} <: AbstractTangentSpace
     coeffs::C
-    TaylorTangent(coeffs) = $(Expr(:new, :(TaylorTangent{typeof(coeffs)}), :coeffs))
+    function TaylorTangent(coeffs)
+        bad_tangent_type = Union{DataType, Symbol, String, Nothing}  # protect against obvious mistakes
+        any(c->isa(c, bad_tangent_type), coeffs) && throw(DomainError(coeffs, "Nonvector-space partial type"))
+        $(Expr(:new, :(TaylorTangent{typeof(coeffs)}), :coeffs))
+    end
 end
 
 """
diff --git a/test/tangent.jl b/test/tangent.jl
index 01a54607..d5ca2af0 100644
--- a/test/tangent.jl
+++ b/test/tangent.jl
@@ -1,4 +1,4 @@
-module tagent
+module tangent
 using Diffractor
 using Diffractor: AbstractZeroBundle, ZeroBundle, DNEBundle
 using Diffractor: TaylorBundle, TaylorTangentIndex
@@ -54,4 +54,12 @@ end
     @test truncate(et, Val(1)) == TaylorTangent((1.0,))
 end
 
+
+@testset "Bad Partial Types" begin
+    @test_throws DomainError TaylorBundle{1}(1.5, (ZeroTangent,))   # mistakenly passing a type rather than a value
+    @test_throws DomainError TaylorBundle{1}(1.5, (:a,))
+    @test_throws DomainError TaylorBundle{1}(1.5, (nothing,))
+    @test_throws DomainError TaylorBundle{1}(1.5, ("x",))
+end
+
 end  # module