diff --git a/src/code_gen/tape_machine.jl b/src/code_gen/tape_machine.jl
index 8441f8c..165b26b 100644
--- a/src/code_gen/tape_machine.jl
+++ b/src/code_gen/tape_machine.jl
@@ -19,7 +19,7 @@ function call_fc(fc::FunctionCall{VectorT, 1}, cache::Dict{Symbol, Any}) where {
 end
 
 function call_fc(fc::FunctionCall{VectorT, 1}, cache::Dict{Symbol, Any}) where {VectorT}
-    cache[fc.return_symbol] = fc.func(fc.additional_arguments[1], getindex.(Ref(cache), fc.arguments))
+    cache[fc.return_symbol] = fc.func(fc.additional_arguments[1], getindex.(Ref(cache), fc.arguments)...)
     return nothing
 end
 
diff --git a/test/unit_tests_qedmodel.jl b/test/unit_tests_qedmodel.jl
index 14a03ac..631a03c 100644
--- a/test/unit_tests_qedmodel.jl
+++ b/test/unit_tests_qedmodel.jl
@@ -37,7 +37,7 @@ testparticleTypesPropagated = [
 
 function compton_groundtruth(input::QEDProcessInput)
     # p1k1 -> p2k2
-    # formula: −(ie)^2 (u(p2) slashed(ε1) S(p2 − k1) slashed(ε2) u(p1) + u(p2) slashed(ε2) S(p1 + k1) slashed(ε1) u(p1))
+    # formula: -(ie)^2 (u(p2) slashed(ε1) S(p2 - k1) slashed(ε2) u(p1) + u(p2) slashed(ε2) S(p1 + k1) slashed(ε1) u(p1))
 
     p1 = input.inFerms[1]
     p2 = input.outFerms[1]