diff --git a/src/print.jl b/src/print.jl
index eb39b0c5468..1c39437a9a0 100644
--- a/src/print.jl
+++ b/src/print.jl
@@ -280,7 +280,7 @@ function Base.show(io::IO, ::MIME"text/latex", ref::ConstraintRef)
 end
 
 """
-    function_string(print_mode::JuMP.PrintMode,
+    function_string(print_mode::Type{<:JuMP.PrintMode},
                     func::Union{JuMP.AbstractJuMPScalar,
                                 Vector{<:JuMP.AbstractJuMPScalar}})
 
@@ -315,13 +315,13 @@ function function_string(print_mode, quad_vector::Vector{<:GenericQuadExpr})
 end
 
 """
-    function_string(print_mode::JuMP.PrintMode,
+    function_string(print_mode::{<:JuMP.PrintMode},
                     constraint::JuMP.AbstractConstraint)
 
 Return a `String` representing the function of the constraint `constraint`
 using print mode `print_mode`.
 """
-function function_string(print_mode::PrintMode, constraint::AbstractConstraint)
+function function_string(print_mode, constraint::AbstractConstraint)
     return function_string(print_mode, jump_function(constraint))
 end
 
@@ -347,7 +347,7 @@ end
 # TODO: Consider fancy latex names for some sets. They're currently printed as
 # regular text in math mode which looks a bit awkward.
 """
-    in_set_string(print_mode::JuMP.PrintMode,
+    in_set_string(print_mode::Type{<:JuMP.PrintMode},
                   set::Union{JuMP.AbstractJuMPScalar,
                              Vector{<:JuMP.AbstractJuMPScalar}})
 
@@ -359,7 +359,7 @@ function in_set_string(print_mode, set::MOI.AbstractSet)
 end
 
 """
-    in_set_string(print_mode::JuMP.PrintMode,
+    in_set_string(print_mode::Type{<:JuMP.PrintMode},
                   constraint::JuMP.AbstractConstraint)
 
 Return a `String` representing the membership to the set of the constraint
@@ -372,8 +372,8 @@ end
 # constraint_object is a JuMP constraint object like AffExprConstraint.
 # Assumes a .func and .set member.
 function constraint_string(print_mode, constraint_name, constraint_object)
-    func_str = function_string(print_mode, constraint_object.func)
-    in_set_str = in_set_string(print_mode, constraint_object.set)
+    func_str = function_string(print_mode, constraint_object)
+    in_set_str = in_set_string(print_mode, constraint_object)
     constraint_without_name = func_str * " " * in_set_str
     if print_mode == IJuliaMode
         constraint_without_name = wrap_in_inline_math_mode(constraint_without_name)
diff --git a/test/print.jl b/test/print.jl
index 3818fa135dc..26137801c1a 100644
--- a/test/print.jl
+++ b/test/print.jl
@@ -44,11 +44,11 @@ struct CustomConstraint{S <: JuMP.AbstractShape} <: JuMP.AbstractConstraint
     in_set_str::String
     shape::S
 end
-function JuMP.function_string(print_mode::JuMP.PrintMode,
+function JuMP.function_string(print_mode,
                               constraint::CustomConstraint)
     return constraint.function_str
 end
-function JuMP.in_set_string(print_mode::JuMP.PrintMode,
+function JuMP.in_set_string(print_mode,
                             constraint::CustomConstraint)
     return constraint.in_set_str
 end
@@ -195,7 +195,7 @@ end
             constraint = CustomConstraint(function_str, in_set_str,
                                           JuMP.ScalarShape())
             cref = JuMP.add_constraint(model, constraint, name)
-            @show string(cref)
+            @test string(cref) == "$name : $function_str $in_set_str"
         end
         test_constraint("fun", "set", "name")
         test_constraint("a", "b", "c")