diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6758b8c..782a558 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.1'
+          - '1.6'
           - '1'
           - nightly
         os:
diff --git a/Project.toml b/Project.toml
index a22e3eb..c6eeec7 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "LsqFit"
 uuid = "2fda8390-95c7-5789-9bda-21331edee243"
-version = "0.13.0"
+version = "0.14.0"
 
 [deps]
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
@@ -15,7 +15,7 @@ Distributions = "0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25"
 ForwardDiff = "0.10"
 NLSolversBase = "7.5"
 StatsAPI = "1"
-julia = "1.1"
+julia = "1.6"
 
 [extras]
 FiniteDiff = "6a86dc24-6348-571c-b903-95158fe2bd41"
diff --git a/src/curve_fit.jl b/src/curve_fit.jl
index 1252d7d..e45fd26 100755
--- a/src/curve_fit.jl
+++ b/src/curve_fit.jl
@@ -299,7 +299,7 @@ function margin_error(fit::LsqFitResult, alpha=0.05; rtol::Real=NaN, atol::Real=
     #   rtol  : relative tolerance for approximate comparisson to 0.0 in negativity check
     std_errors = stderror(fit; rtol=rtol, atol=atol)
     dist = TDist(dof(fit))
-    critical_values = quantile(dist, 1 - alpha / 2)
+    critical_values = eltype(coef(fit))(quantile(dist, Float64(1 - alpha / 2)))
     # scale standard errors by quantile of the student-t distribution (critical values)
     return std_errors * critical_values
 end