diff --git a/Project.toml b/Project.toml
index 033930d7c..5adbe274c 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "Distributions"
 uuid = "31c24e10-a181-5473-b8eb-7969acd0382f"
 authors = ["JuliaStats"]
-version = "0.25.120"
+version = "0.25.121"
 
 [deps]
 AliasTables = "66dad0bd-aa9a-41b7-9441-69ab47430ed8"
diff --git a/src/multivariate/mvnormal.jl b/src/multivariate/mvnormal.jl
index 5806c00f3..fa6414236 100644
--- a/src/multivariate/mvnormal.jl
+++ b/src/multivariate/mvnormal.jl
@@ -261,6 +261,25 @@ logdetcov(d::MvNormal) = logdet(d.Σ)
 
 sqmahal(d::MvNormal, x::AbstractVector) = invquad(d.Σ, x .- d.μ)
 
+function sqmahal(d::DiagNormal, x::AbstractVector)
+    # Faster than above as this avoids calculating (x .- d.µ)
+    T = promote_type(partype(d), eltype(x))
+    sum = zero(T)
+    for i in eachindex(x)
+        @inbounds sum += abs2(x[i] - d.μ[i]) / d.Σ[i, i]
+    end
+    return sum
+end
+
+function sqmahal(d::IsoNormal, x::AbstractVector)
+    T = promote_type(partype(d), eltype(x))
+    sum = zero(T)
+    for i in eachindex(x)
+        @inbounds sum += abs2(x[i] - d.μ[i])
+    end
+    return sum / d.Σ[1, 1]
+end
+
 sqmahal!(r::AbstractVector, d::MvNormal, x::AbstractMatrix) =
     invquad!(r, d.Σ, x .- d.μ)