diff --git a/.gitignore b/.gitignore
index b25c15b..93bfd12 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 *~
+.DS_Store
diff --git a/src/MAT_HDF5.jl b/src/MAT_HDF5.jl
index 22f1efa..9d2e80c 100644
--- a/src/MAT_HDF5.jl
+++ b/src/MAT_HDF5.jl
@@ -172,6 +172,11 @@ function m_read(dset::HDF5Dataset)
 
     # Regular arrays of values
     # Convert to Julia type
+    if !haskey(str2type_matlab, mattype)
+        @warn "Class not convertable - skipping field - set value to missing"
+        return missing
+    end
+
     T = str2type_matlab[mattype]
 
     # Check for a COMPOUND data set, and if so handle complex numbers specially
@@ -207,6 +212,11 @@ function m_read(g::HDF5Group)
                 # This matrix is not empty.
                 ir = add!(convert(Vector{Int}, read(g, "ir")), 1)
                 dset = g["data"]
+                if !haskey(str2type_matlab, mattype)
+                    @warn "Class not convertable - skipping field - set value to missing"
+                    return missing
+                end
+
                 T = str2type_matlab[mattype]
                 try
                     dtype = datatype(dset)
@@ -258,6 +268,9 @@ function read(f::MatlabHDF5File, name::String)
     obj = f.plain[name]
     try
         val = m_read(obj)
+    catch
+        @warn "Field not readable - skipping field - set value to missing"
+        val = missing
     finally
         close(obj)
     end
diff --git a/src/MAT_v5.jl b/src/MAT_v5.jl
index 789affb..a6635d6 100644
--- a/src/MAT_v5.jl
+++ b/src/MAT_v5.jl
@@ -100,8 +100,13 @@ function read_bswap(f::IO, swap_bytes::Bool, d::AbstractArray{T}) where T
     d
 end
 
-skip_padding(f::IO, nbytes::Int, hbytes::Int) = if nbytes % hbytes != 0
-    skip(f, hbytes-(nbytes % hbytes))
+function skip_padding(f::IO, nbytes::Int, hbytes::Int)
+    if nbytes % hbytes != 0
+        skip(f, hbytes-(nbytes % hbytes))
+        return hbytes-(nbytes % hbytes)
+    else
+        return 0
+    end
 end
 
 # Read data type and number of bytes at the start of a data element
@@ -121,8 +126,9 @@ end
 function read_element(f::IO, swap_bytes::Bool, ::Type{T}) where T
     (dtype, nbytes, hbytes) = read_header(f, swap_bytes)
     data = read_bswap(f, swap_bytes, T, Int(div(nbytes, sizeof(T))))
-    skip_padding(f, nbytes, hbytes)
-    data
+    skipped_bytes = skip_padding(f, nbytes, hbytes)
+    bytes_read = nbytes + hbytes + skipped_bytes
+    return data, bytes_read
 end
 
 # Read data element as encoded type
@@ -168,10 +174,11 @@ end
 
 function read_struct(f::IO, swap_bytes::Bool, dimensions::Vector{Int32}, is_object::Bool)
     if is_object
-        class = String(read_element(f, swap_bytes, UInt8))
+        class = String(read_element(f, swap_bytes, UInt8)[1])
     end
-    field_length = read_element(f, swap_bytes, Int32)[1]
-    field_names = read_element(f, swap_bytes, UInt8)
+    field_lengths, _ = read_element(f, swap_bytes, Int32)
+    field_length = field_lengths[1]
+    field_names, _ = read_element(f, swap_bytes, UInt8)
     n_fields = div(length(field_names), field_length)
 
     # Get field names as strings
@@ -232,11 +239,11 @@ function read_sparse(f::IO, swap_bytes::Bool, dimensions::Vector{Int32}, flags::
 
     m = isempty(dimensions) ? 0 : dimensions[1]
     n = length(dimensions) <= 1 ? 0 : dimensions[2]
-    ir = plusone!(convert(Vector{Int}, read_element(f, swap_bytes, Int32)))
-    jc = plusone!(convert(Vector{Int}, read_element(f, swap_bytes, Int32)))
+    ir = plusone!(convert(Vector{Int}, read_element(f, swap_bytes, Int32)[1]))
+    jc = plusone!(convert(Vector{Int}, read_element(f, swap_bytes, Int32)[1]))
     if (flags[1] & (1 << 9)) != 0 # logical
         # WTF. For some reason logical sparse matrices are tagged as doubles.
-        pr = read_element(f, swap_bytes, Bool)
+        pr = read_element(f, swap_bytes, Bool)[1]
     else
         pr = read_data(f, swap_bytes)
         if (flags[1] & (1 << 11)) != 0 # complex
@@ -316,9 +323,10 @@ function read_matrix(f::IO, swap_bytes::Bool)
         return ("", Matrix{Union{}}(undef, 0, 0))
     end
 
-    flags = read_element(f, swap_bytes, UInt32)
-    dimensions = read_element(f, swap_bytes, Int32)
-    name = String(read_element(f, swap_bytes, UInt8))
+    flags, f_bytes = read_element(f, swap_bytes, UInt32)
+    dimensions, d_bytes = read_element(f, swap_bytes, Int32)
+    raw_name, n_bytes = read_element(f, swap_bytes, UInt8)
+    name = String(raw_name)
 
     class = flags[1] & 0xFF
     local data
@@ -330,6 +338,11 @@ function read_matrix(f::IO, swap_bytes::Bool)
         data = read_sparse(f, swap_bytes, dimensions, flags)
     elseif class == mxCHAR_CLASS && length(dimensions) <= 2
         data = read_string(f, swap_bytes, dimensions)
+    elseif class > length(CONVERT_TYPES) # undocumented classes
+        @warn "Class not convertable - skipping field - set value to missing"
+        remaining_bytes = nbytes - f_bytes - d_bytes - n_bytes
+        skip(f, remaining_bytes)
+        data = missing
     else
         if (flags[1] & (1 << 9)) != 0 # logical
             data = read_data(f, swap_bytes, Bool, dimensions)
@@ -378,7 +391,7 @@ function getvarnames(matfile::Matlabv5File)
 
             read_element(f, matfile.swap_bytes, UInt32)
             read_element(f, matfile.swap_bytes, Int32)
-            varnames[String(read_element(f, matfile.swap_bytes, UInt8))] = offset
+            varnames[String(read_element(f, matfile.swap_bytes, UInt8)[1])] = offset
 
             seek(matfile.ios, offset+nbytes+hbytes)
         end
diff --git a/test/read.jl b/test/read.jl
index 6e00483..9567014 100644
--- a/test/read.jl
+++ b/test/read.jl
@@ -1,8 +1,9 @@
 using MAT, Test
 
-function check(filename, result)
+function check(filename, result; skip_keys=String[])
     matfile = matopen(filename)
     for (k, v) in result
+        k in skip_keys && continue
         @test exists(matfile, k)
         got = read(matfile, k)
         if !isequal(got, v) || (typeof(got) != typeof(v) && (!isa(got, String) || !(isa(v, String))))
@@ -20,24 +21,28 @@ function check(filename, result)
                 """)
         end
     end
-    @test union!(Set(), names(matfile)) == union!(Set(), keys(result))
+    if isempty(skip_keys)
+        @test union!(Set(), names(matfile)) == union!(Set(), keys(result))
+    end
     close(matfile)
 
-    mat = matread(filename)
-    if !isequal(mat, result)
-        error("""
-            Data mismatch reading $filename ($format)
+    if isempty(skip_keys)
+        mat = matread(filename)
+        if !isequal(mat, result)
+            error("""
+                Data mismatch reading $filename ($format)
 
-            Got:
+                Got:
 
-            $(repr(mat))
+                $(repr(mat))
 
-            Expected:
+                Expected:
 
-            $(repr(result))
-            """)
-        close(matfile)
-        return false
+                $(repr(result))
+                """)
+            close(matfile)
+            return false
+        end
     end
 
     return true
@@ -136,6 +141,18 @@ for _format in ["v6", "v7", "v7.3"]
     )
     check("sparse.mat", result)
 
+    result = Dict(
+        "t" => Dict(
+            "int" => 66.0,
+            "struct" => Dict{String,Any}(
+                "b"=>[5.0 6.0 7.0],
+                "a"=>[1.0 2.0 3.0]),
+            "skip_field" => missing
+        )
+    )
+
+    check("skip_field.mat", result, skip_keys=["", "#subsystem#"])
+
     matfile = matopen("partial.mat")
     var1 = read(matfile, "var1")
     @assert var1[28, 33] == 5
diff --git a/test/v6/skip_field.mat b/test/v6/skip_field.mat
new file mode 100644
index 0000000..d44dce2
Binary files /dev/null and b/test/v6/skip_field.mat differ
diff --git a/test/v7.3/skip_field.mat b/test/v7.3/skip_field.mat
new file mode 100644
index 0000000..e67d60d
Binary files /dev/null and b/test/v7.3/skip_field.mat differ
diff --git a/test/v7/skip_field.mat b/test/v7/skip_field.mat
new file mode 100644
index 0000000..163bf34
Binary files /dev/null and b/test/v7/skip_field.mat differ
diff --git a/test/write.jl b/test/write.jl
index 3b8c910..b6b219d 100644
--- a/test/write.jl
+++ b/test/write.jl
@@ -14,7 +14,17 @@ function test_write(data)
 	end
 
 	if !isequal(result, data)
-		error("Data mismatch")
+		error("""
+            Data mismatch
+
+            Got:
+
+            $(repr(result))
+
+            Expected:
+
+            $(repr(data))
+            """)
 	end
 end