diff --git a/src/parameter_caches.jl b/src/parameter_caches.jl
index 824b2e2a..42d040e8 100644
--- a/src/parameter_caches.jl
+++ b/src/parameter_caches.jl
@@ -22,7 +22,7 @@ function linear_interpolation_parameters(u::AbstractArray{T, N}, t, idx) where {
     Δu = if N > 1
         ax = axes(u)
         safe_diff.(
-            u[ax[1:(end - 1)]..., (idx + 1):(idx + 1)], u[ax[1:(end - 1)]..., idx:idx])
+            u[ax[1:(end - 1)]..., (idx + 1)], u[ax[1:(end - 1)]..., idx])
     else
         safe_diff(u[idx + 1], u[idx])
     end
diff --git a/test/interpolation_tests.jl b/test/interpolation_tests.jl
index 69e5c197..3ebc1741 100644
--- a/test/interpolation_tests.jl
+++ b/test/interpolation_tests.jl
@@ -43,11 +43,11 @@ end
         A = LinearInterpolation(u, t; extrapolate = true)
 
         for (_t, _u) in zip(t, eachcol(u))
-            @test A(_t) == reshape(_u, :, 1)
+            @test A(_t) == _u
         end
-        @test A(0) == [0.0; 0.0;;]
-        @test A(5.5) == [11.0; 16.5;;]
-        @test A(11) == [22; 33;;]
+        @test A(0) == [0.0, 0.0]
+        @test A(5.5) == [11.0, 16.5]
+        @test A(11) == [22, 33]
 
         x = 1:10
         y = 2:4