diff --git a/src/chain_rules.jl b/src/chain_rules.jl
index fdeb75d8..2e3b9919 100644
--- a/src/chain_rules.jl
+++ b/src/chain_rules.jl
@@ -18,10 +18,10 @@ end
 function ChainRulesCore.frule((_, Δp, _), ::typeof(differentiate), p, x)
     return differentiate(p, x), differentiate(Δp, x)
 end
-function pullback(Δdpdx, x)
+function pullback_differentiate_polynomial(Δdpdx, x)
     return ChainRulesCore.NoTangent(), x * differentiate(x * Δdpdx, x), ChainRulesCore.NoTangent()
 end
-function ChainRulesCore.rrule(::typeof(differentiate), p, x)
+function ChainRulesCore.rrule(::typeof(differentiate), p::APL, x)
     dpdx = differentiate(p, x)
-    return dpdx, Base.Fix2(pullback, x)
+    return dpdx, Base.Fix2(pullback_differentiate_polynomial, x)
 end