diff --git a/src/diagonal.jl b/src/diagonal.jl
index ddee8981..94e7cacd 100644
--- a/src/diagonal.jl
+++ b/src/diagonal.jl
@@ -349,6 +349,8 @@ end
 
 function rmul!(A::AbstractMatrix, D::Diagonal)
     matmul_size_check(size(A), size(D))
+    axes(A, 2) == axes(D.diag, 1) ||
+        throw(ArgumentError(lazy"second axis of A, $(axes(A,2)), does not match first axis of D, $(axes(D, 1))"))
     for I in CartesianIndices(A)
         row, col = Tuple(I)
         @inbounds A[row, col] *= D.diag[col]
@@ -370,6 +372,8 @@ end
 
 function lmul!(D::Diagonal, B::AbstractVecOrMat)
     matmul_size_check(size(D), size(B))
+    axes(D.diag, 1) == axes(B, 1) ||
+        throw(ArgumentError(lazy"second axis of D, $(axes(D, 2)), does not match first axis of B, $(axes(B, 1))"))
     for I in CartesianIndices(B)
         row = I[1]
         @inbounds B[I] = D.diag[row] * B[I]
diff --git a/test/diagonal.jl b/test/diagonal.jl
index f83ad392..ee78bad5 100644
--- a/test/diagonal.jl
+++ b/test/diagonal.jl
@@ -955,7 +955,9 @@ end
     D = Diagonal(1:4)
     A = OffsetArray(rand(4,4), 2, 2)
     @test_throws ArgumentError D * A
+    @test_throws ArgumentError lmul!(D, A)
     @test_throws ArgumentError A * D
+    @test_throws ArgumentError rmul!(A, D)
     @test_throws ArgumentError mul!(similar(A, size(A)), A, D)
     @test_throws ArgumentError mul!(similar(A, size(A)), D, A)
 end