diff --git a/Cargo.lock b/Cargo.lock
index c16249e2..0b8dcdd2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1069,9 +1069,9 @@ checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
 
 [[package]]
 name = "pdf-writer"
-version = "0.10.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af6a7882fda7808481d43c51cadfc3ec934c6af72612a1fe6985ce329a2f0469"
+checksum = "be17f48d7fbbd22c6efedb58af5d409aa578e407f40b29a0bcb4e66ed84c5c98"
 dependencies = [
  "bitflags 2.6.0",
  "itoa",
@@ -1546,8 +1546,9 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "subsetter"
-version = "0.11.0"
-source = "git+https://github.com/typst/subsetter?rev=4e0058b#4e0058b4b9a0948a5f79894111948d95e59ba350"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "74f98178f34057d4d4de93d68104007c6dea4dfac930204a69ab4622daefa648"
 
 [[package]]
 name = "svg2pdf"
diff --git a/Cargo.toml b/Cargo.toml
index e1102190..8c9b03e8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,13 +22,13 @@ image = { version = "0.25", default-features = false, features = ["jpeg", "png",
 miniz_oxide = "0.8"
 once_cell = "1.18"
 oxipng = { version = "9", default-features = false, features = ["filetime", "parallel", "zopfli"] }
-pdf-writer = "0.10"
+pdf-writer = "0.12"
 pdfium-render = "=0.8.20"
 termcolor = "1.2"
 usvg = { version = "0.43", default-features = false }
 tiny-skia = "0.11.4"
 resvg = { version = "0.43", default-features = false }
-subsetter = { git = "https://github.com/typst/subsetter", rev = "4e0058b" }
+subsetter = "0.2"
 ttf-parser = { version = "0.24.1" }
 siphasher = { version = "1.0.1"}
 
diff --git a/cli/src/main.rs b/cli/src/main.rs
index 6e5b9b07..cbb0fed5 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -27,6 +27,7 @@ fn run() -> Result<(), String> {
             compress: true,
             embed_text: !args.text_to_paths,
             raster_scale: args.raster_scale,
+            pdfa: false,
         };
 
         let page_options = PageOptions { dpi: args.dpi };
diff --git a/src/lib.rs b/src/lib.rs
index 701e0715..99086cda 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -67,7 +67,7 @@ use usvg::{Size, Transform, Tree};
 
 use crate::render::{tree_to_stream, tree_to_xobject};
 use crate::util::context::Context;
-use crate::util::helper::{deflate, RectExt, TransformExt};
+use crate::util::helper::{deflate, ContentExt, RectExt, TransformExt};
 use crate::util::resources::ResourceContainer;
 
 // The ICC profiles.
@@ -96,6 +96,11 @@ impl Default for PageOptions {
 pub enum ConversionError {
     /// The SVG image contains an unrecognized type of image.
     InvalidImage,
+    /// Text shaping resulted in a .notdef glyph. Can only occur if PDF/A
+    /// processing is enabled.
+    MissingGlyphs,
+    /// Converting the SVG would require too much nesting depth.
+    TooMuchNesting,
     /// An unknown error occurred during the conversion. This could indicate a bug in the
     /// svg2pdf.
     UnknownError,
@@ -111,6 +116,8 @@ impl Display for ConversionError {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         match self {
             Self::InvalidImage => f.write_str("An unknown type of image appears in the SVG."),
+            Self::MissingGlyphs => f.write_str("A piece of text could not be displayed with any font."),
+            Self::TooMuchNesting => f.write_str("The SVG's nesting depth is too high."),
             Self::UnknownError => f.write_str("An unknown error occurred during the conversion. This could indicate a bug in svg2pdf"),
             #[cfg(feature = "text")]
             Self::SubsetError(_) => f.write_str("An error occurred while subsetting a font."),
@@ -148,6 +155,13 @@ pub struct ConversionOptions {
     ///
     /// _Default:_ `true`.
     pub embed_text: bool,
+
+    /// Whether to write chunks in PDF/A-2b compliant mode.
+    ///
+    /// **Note:** This currently only ensures that `to_chunk` does not generate
+    /// anything that is forbidden by PDF/A. It does _not_ turn the
+    /// free-standing PDF generated by `to_pdf` into a valid PDF/A.
+    pub pdfa: bool,
 }
 
 impl Default for ConversionOptions {
@@ -156,6 +170,7 @@ impl Default for ConversionOptions {
             compress: true,
             raster_scale: 1.5,
             embed_text: true,
+            pdfa: false,
         }
     }
 }
@@ -190,7 +205,7 @@ pub fn to_pdf(
     conversion_options: ConversionOptions,
     page_options: PageOptions,
 ) -> Result<Vec<u8>> {
-    let mut ctx = Context::new(tree, conversion_options);
+    let mut ctx = Context::new(tree, conversion_options)?;
     let mut pdf = Pdf::new();
 
     let dpi_ratio = 72.0 / page_options.dpi;
@@ -210,7 +225,7 @@ pub fn to_pdf(
     // Generate main content
     let mut rc = ResourceContainer::new();
     let mut content = Content::new();
-    content.save_state();
+    content.save_state_checked()?;
     content.transform(dpi_transform.to_pdf_transform());
     tree_to_stream(tree, &mut pdf, &mut content, &mut ctx, &mut rc)?;
     content.restore_state();
@@ -347,7 +362,7 @@ pub fn to_chunk(
 ) -> Result<(Chunk, Ref)> {
     let mut chunk = Chunk::new();
 
-    let mut ctx = Context::new(tree, conversion_options);
+    let mut ctx = Context::new(tree, conversion_options)?;
     let x_ref = tree_to_xobject(tree, &mut chunk, &mut ctx)?;
     ctx.write_global_objects(&mut chunk)?;
     Ok((chunk, x_ref))
diff --git a/src/render/clip_path.rs b/src/render/clip_path.rs
index bf3a36f7..58292577 100644
--- a/src/render/clip_path.rs
+++ b/src/render/clip_path.rs
@@ -6,7 +6,9 @@ use usvg::{ClipPath, FillRule, Group, Node, Transform};
 use super::group;
 use super::path::draw_path;
 use crate::util::context::Context;
-use crate::util::helper::{bbox_to_non_zero_rect, NameExt, RectExt, TransformExt};
+use crate::util::helper::{
+    bbox_to_non_zero_rect, ContentExt, NameExt, RectExt, TransformExt,
+};
 use crate::util::resources::ResourceContainer;
 use crate::Result;
 
@@ -181,7 +183,7 @@ fn create_complex_clip_path(
     let x_ref = ctx.alloc_ref();
 
     let mut content = Content::new();
-    content.save_state();
+    content.save_state_checked()?;
 
     if let Some(clip_path) = clip_path.clip_path() {
         render(parent, clip_path, chunk, &mut content, ctx, &mut rc)?;
diff --git a/src/render/group.rs b/src/render/group.rs
index e27a46d5..30ebc83e 100644
--- a/src/render/group.rs
+++ b/src/render/group.rs
@@ -7,7 +7,9 @@ use usvg::{Opacity, Transform};
 use super::filter;
 use super::{clip_path, mask, Render};
 use crate::util::context::Context;
-use crate::util::helper::{BlendModeExt, GroupExt, NameExt, RectExt, TransformExt};
+use crate::util::helper::{
+    BlendModeExt, ContentExt, GroupExt, NameExt, RectExt, TransformExt,
+};
 use crate::util::resources::ResourceContainer;
 use crate::Result;
 
@@ -36,7 +38,7 @@ pub fn render(
     let initial_opacity = initial_opacity.unwrap_or(Opacity::ONE);
 
     if group.is_isolated() || initial_opacity.get() != 1.0 {
-        content.save_state();
+        content.save_state_checked()?;
         let gs_ref = ctx.alloc_ref();
         let mut gs = chunk.ext_graphics(gs_ref);
         gs.non_stroking_alpha(group.opacity().mul(initial_opacity).get())
@@ -126,7 +128,7 @@ fn create_to_stream(
     accumulated_transform: Transform,
     rc: &mut ResourceContainer,
 ) -> Result<()> {
-    content.save_state();
+    content.save_state_checked()?;
     content.transform(group.transform().to_pdf_transform());
     let accumulated_transform = accumulated_transform.pre_concat(group.transform());
 
diff --git a/src/render/image.rs b/src/render/image.rs
index 9a7ee46b..d539226c 100644
--- a/src/render/image.rs
+++ b/src/render/image.rs
@@ -8,7 +8,7 @@ use usvg::{ImageKind, Rect, Size, Transform, Tree};
 
 use crate::render::tree_to_xobject;
 use crate::util::context::Context;
-use crate::util::helper::{NameExt, TransformExt};
+use crate::util::helper::{ContentExt, NameExt, TransformExt};
 use crate::util::resources::ResourceContainer;
 use crate::Result;
 
@@ -59,7 +59,7 @@ pub fn render(
         Rect::from_xywh(0.0, 0.0, image_size.width(), image_size.height()).unwrap(),
     );
 
-    content.save_state();
+    content.save_state_checked()?;
 
     // Account for the x/y of the viewbox.
     content.transform(
diff --git a/src/render/mask.rs b/src/render/mask.rs
index 058ac7c0..252b2b42 100644
--- a/src/render/mask.rs
+++ b/src/render/mask.rs
@@ -3,7 +3,7 @@ use usvg::{Group, Mask, Transform};
 
 use super::group;
 use crate::util::context::Context;
-use crate::util::helper::{clip_to_rect, MaskTypeExt, NameExt, RectExt};
+use crate::util::helper::{clip_to_rect, ContentExt, MaskTypeExt, NameExt, RectExt};
 use crate::util::resources::ResourceContainer;
 use crate::Result;
 
@@ -34,7 +34,7 @@ pub fn create(
     let mut rc = ResourceContainer::new();
 
     let mut content = Content::new();
-    content.save_state();
+    content.save_state_checked()?;
 
     if let Some(mask) = mask.mask() {
         render(parent, mask, chunk, &mut content, ctx, &mut rc)?;
diff --git a/src/render/mod.rs b/src/render/mod.rs
index 661e5c79..91ade5bd 100644
--- a/src/render/mod.rs
+++ b/src/render/mod.rs
@@ -2,7 +2,7 @@ use pdf_writer::{Chunk, Content, Filter, Finish, Ref};
 use usvg::{Node, Transform, Tree};
 
 use crate::util::context::Context;
-use crate::util::helper::{RectExt, TransformExt};
+use crate::util::helper::{ContentExt, RectExt, TransformExt};
 use crate::util::resources::ResourceContainer;
 use crate::Result;
 
@@ -28,7 +28,7 @@ pub fn tree_to_stream(
     ctx: &mut Context,
     rc: &mut ResourceContainer,
 ) -> Result<()> {
-    content.save_state();
+    content.save_state_checked()?;
 
     // From PDF coordinate system to SVG coordinate system
     let initial_transform =
diff --git a/src/render/path.rs b/src/render/path.rs
index 6e6f39b7..ffec45e1 100644
--- a/src/render/path.rs
+++ b/src/render/path.rs
@@ -8,7 +8,7 @@ use usvg::{Stroke, Transform};
 
 use super::{gradient, pattern};
 use crate::util::context::Context;
-use crate::util::helper::{ColorExt, LineCapExt, LineJoinExt, NameExt};
+use crate::util::helper::{ColorExt, ContentExt, LineCapExt, LineJoinExt, NameExt};
 use crate::util::resources::ResourceContainer;
 use crate::Result;
 
@@ -104,6 +104,7 @@ pub(crate) fn stroke_path(
     let operation = |content: &mut Content, stroke: &Stroke| {
         draw_path(path.data().segments(), content);
         finish_path(Some(stroke), None, content);
+        Ok(())
     };
 
     if let Some(path_stroke) = path.stroke() {
@@ -131,13 +132,13 @@ pub(crate) fn stroke(
     content: &mut Content,
     ctx: &mut Context,
     rc: &mut ResourceContainer,
-    operation: impl Fn(&mut Content, &Stroke),
+    operation: impl Fn(&mut Content, &Stroke) -> Result<()>,
     accumulated_transform: Transform,
     bbox: Rect,
 ) -> Result<()> {
     let paint = &stroke.paint();
 
-    content.save_state();
+    content.save_state_checked()?;
 
     match paint {
         Paint::Color(c) => {
@@ -206,7 +207,7 @@ pub(crate) fn stroke(
         content.set_dash_pattern(vec![], 0.0);
     }
 
-    operation(content, stroke);
+    operation(content, stroke)?;
 
     content.restore_state();
 
@@ -229,6 +230,7 @@ pub(crate) fn fill_path(
     let operation = |content: &mut Content, fill: &Fill| {
         draw_path(path.data().segments(), content);
         finish_path(None, Some(fill), content);
+        Ok(())
     };
 
     if let Some(path_fill) = path.fill() {
@@ -256,13 +258,13 @@ pub(crate) fn fill(
     content: &mut Content,
     ctx: &mut Context,
     rc: &mut ResourceContainer,
-    operation: impl Fn(&mut Content, &Fill),
+    operation: impl Fn(&mut Content, &Fill) -> Result<()>,
     accumulated_transform: Transform,
     bbox: Rect,
 ) -> Result<()> {
     let paint = &fill.paint();
 
-    content.save_state();
+    content.save_state_checked()?;
 
     match paint {
         Paint::Color(c) => {
@@ -307,7 +309,7 @@ pub(crate) fn fill(
         }
     }
 
-    operation(content, fill);
+    operation(content, fill)?;
     content.restore_state();
 
     Ok(())
diff --git a/src/render/text.rs b/src/render/text.rs
index 45c79263..d9fe6577 100644
--- a/src/render/text.rs
+++ b/src/render/text.rs
@@ -1,13 +1,14 @@
 use crate::render::path;
 use crate::util::allocate::RefAllocator;
 use crate::util::context::Context;
-use crate::util::helper::{deflate, TransformExt};
+use crate::util::helper::{deflate, ContentExt, TransformExt};
 use crate::util::resources::ResourceContainer;
-use crate::ConversionError::{InvalidFont, SubsetError, UnknownError};
+use crate::ConversionError::{self, InvalidFont, SubsetError};
 use crate::Result;
 use pdf_writer::types::{
     CidFontType, FontFlags, SystemInfo, TextRenderingMode, UnicodeCmap,
 };
+use pdf_writer::writers::WMode;
 use pdf_writer::{Chunk, Content, Filter, Finish, Name, Ref, Str};
 use siphasher::sip128::{Hasher128, SipHasher13};
 use std::collections::{BTreeMap, HashMap};
@@ -19,6 +20,10 @@ use usvg::{Fill, Group, ImageKind, Node, PaintOrder, Stroke, Transform};
 
 const CFF: Tag = Tag::from_bytes(b"CFF ");
 const CFF2: Tag = Tag::from_bytes(b"CFF2");
+
+const SUBSET_TAG_LEN: usize = 6;
+const IDENTITY_H: &str = "Identity-H";
+
 const CMAP_NAME: Name = Name(b"Custom");
 const SYSTEM_INFO: SystemInfo = SystemInfo {
     registry: Str(b"Adobe"),
@@ -57,18 +62,14 @@ pub fn write_font(
         .or_else(|| ttf.raw_face().table(CFF2))
         .is_some();
 
-    let postscript_name = find_name(&ttf, name_id::POST_SCRIPT_NAME)
-        .unwrap_or_else(|| "unknown".to_string());
-
-    let subset_tag = subset_tag(glyph_set)?;
-    let base_font = format!("{subset_tag}+{postscript_name}");
+    let base_font = base_font_name(&ttf, glyph_set);
     let base_font_type0 =
-        if is_cff { format!("{base_font}-Identity-H") } else { base_font.clone() };
+        if is_cff { format!("{base_font}-{IDENTITY_H}") } else { base_font.clone() };
 
     chunk
         .type0_font(type0_ref)
         .base_font(Name(base_font_type0.as_bytes()))
-        .encoding_predefined(Name(b"Identity-H"))
+        .encoding_predefined(Name(IDENTITY_H.as_bytes()))
         .descendant_font(cid_ref)
         .to_unicode(cmap_ref);
 
@@ -106,7 +107,11 @@ pub fn write_font(
     cid.finish();
 
     let mut flags = FontFlags::empty();
-    flags.set(FontFlags::SERIF, postscript_name.contains("Serif"));
+    flags.set(
+        FontFlags::SERIF,
+        find_name(&ttf, name_id::POST_SCRIPT_NAME)
+            .is_some_and(|name| name.contains("Serif")),
+    );
     flags.set(FontFlags::FIXED_PITCH, ttf.is_monospaced());
     flags.set(FontFlags::ITALIC, ttf.is_italic());
     flags.insert(FontFlags::SYMBOLIC);
@@ -154,7 +159,7 @@ pub fn write_font(
     font_descriptor.finish();
 
     let cmap = create_cmap(glyph_set, glyph_remapper).ok_or(SubsetError(font.id))?;
-    chunk.cmap(cmap_ref, &cmap.finish());
+    chunk.cmap(cmap_ref, &cmap.finish()).writing_mode(WMode::Horizontal);
 
     // Subset and write the font's bytes.
     let data = subset_font(&font.face_data, font.face_index, glyph_remapper, font.id)?;
@@ -234,7 +239,7 @@ pub fn render(
             continue;
         }
 
-        let operation = |content: &mut Content| {
+        let operation = |content: &mut Content| -> Result<()> {
             for glyph in &span.positioned_glyphs {
                 let Some(font) = fonts.get(&glyph.font).and_then(|f| f.as_ref()) else {
                     continue;
@@ -243,6 +248,9 @@ pub fn render(
                 let name = font_names.get(&font.reference).unwrap();
 
                 // TODO: Remove unwraps and switch to error-based handling.
+                // NOTE(laurmaedje): If it can't happen, I think a panic is
+                // better. There is no way to handle it as a consumer of
+                // svg2pdf.
                 let cid = font.glyph_remapper.get(glyph.id.0).unwrap();
                 let ts = glyph
                     .outline_transform()
@@ -251,7 +259,7 @@ pub fn render(
                     // we want to leverage the native PDF font size feature instead, so we downscale
                     // it to a font size of 1.
                     .pre_scale(1.0 / span.font_size.get(), 1.0 / span.font_size.get());
-                content.save_state();
+                content.save_state_checked()?;
                 content.begin_text();
                 content.set_text_matrix(ts.to_pdf_transform());
                 content.set_font(Name(name.as_bytes()), span.font_size.get());
@@ -259,16 +267,18 @@ pub fn render(
                 content.end_text();
                 content.restore_state();
             }
+
+            Ok(())
         };
 
-        let stroke_operation = |content: &mut Content, _: &Stroke| {
+        let stroke_operation = |content: &mut Content, _: &Stroke| -> Result<()> {
             content.set_text_rendering_mode(TextRenderingMode::Stroke);
-            operation(content);
+            operation(content)
         };
 
-        let fill_operation = |content: &mut Content, _: &Fill| {
+        let fill_operation = |content: &mut Content, _: &Fill| -> Result<()> {
             content.set_text_rendering_mode(TextRenderingMode::Fill);
-            operation(content);
+            operation(content)
         };
 
         if let Some(overline) = &span.overline {
@@ -279,7 +289,7 @@ pub fn render(
             path::render(underline, chunk, content, ctx, rc, accumulated_transform)?;
         }
 
-        content.save_state();
+        content.save_state_checked()?;
         match (span.fill.as_ref(), span.stroke.as_ref()) {
             (Some(fill), Some(stroke)) => match span.paint_order {
                 PaintOrder::FillAndStroke => {
@@ -353,7 +363,7 @@ pub fn render(
             }
             (None, None) => {
                 content.set_text_rendering_mode(TextRenderingMode::Invisible);
-                operation(content);
+                operation(content)?;
             }
         };
 
@@ -367,17 +377,36 @@ pub fn render(
     Ok(())
 }
 
+/// Creates the base font name for a font with a specific glyph subset.
+/// Consists of a subset tag and the PostScript name of the font.
+///
+/// Returns a string of length maximum 116, so that even with `-Identity-H`
+/// added it does not exceed the maximum PDF/A name length of 127.
+fn base_font_name<T: Hash>(ttf: &Face, glyphs: &T) -> String {
+    const MAX_LEN: usize = 127 - REST_LEN;
+    const REST_LEN: usize = SUBSET_TAG_LEN + 1 + 1 + IDENTITY_H.len();
+
+    let postscript_name = find_name(ttf, name_id::POST_SCRIPT_NAME);
+    let name = postscript_name.as_deref().unwrap_or("unknown");
+    let trimmed = &name[..name.len().min(MAX_LEN)];
+
+    // Hash the full name (we might have trimmed) and the glyphs to produce
+    // a fairly unique subset tag.
+    let subset_tag = subset_tag(&(name, glyphs));
+
+    format!("{subset_tag}+{trimmed}")
+}
+
 /// Produce a unique 6 letter tag for a glyph set.
-fn subset_tag(glyphs: &mut BTreeMap<u16, String>) -> Result<String> {
-    const LEN: usize = 6;
+fn subset_tag<T: Hash>(glyphs: &T) -> String {
     const BASE: u128 = 26;
     let mut hash = hash128(&glyphs);
-    let mut letter = [b'A'; LEN];
+    let mut letter = [b'A'; SUBSET_TAG_LEN];
     for l in letter.iter_mut() {
         *l = b'A' + (hash % BASE) as u8;
         hash /= BASE;
     }
-    Ok(std::str::from_utf8(&letter).map_err(|_| UnknownError)?.to_string())
+    std::str::from_utf8(&letter).unwrap().into()
 }
 
 /// Calculate a 128-bit siphash of a value.
@@ -479,7 +508,11 @@ pub struct Font {
     pub face_index: u32,
 }
 
-pub fn fill_fonts(group: &Group, ctx: &mut Context, fontdb: &fontdb::Database) {
+pub fn fill_fonts(
+    group: &Group,
+    ctx: &mut Context,
+    fontdb: &fontdb::Database,
+) -> Result<()> {
     for child in group.children() {
         match child {
             Node::Text(t) => {
@@ -518,18 +551,28 @@ pub fn fill_fonts(group: &Group, ctx: &mut Context, fontdb: &fontdb::Database) {
                             font.glyph_set.insert(g.id.0, g.text.clone());
                             font.glyph_remapper.remap(g.id.0);
                         }
+
+                        if ctx.options.pdfa && g.id.0 == 0 {
+                            return Err(ConversionError::MissingGlyphs);
+                        }
                     }
                 }
             }
-            Node::Group(group) => fill_fonts(group, ctx, fontdb),
+            Node::Group(group) => fill_fonts(group, ctx, fontdb)?,
             Node::Image(image) => {
                 if let ImageKind::SVG(svg) = image.kind() {
-                    fill_fonts(svg.root(), ctx, fontdb);
+                    fill_fonts(svg.root(), ctx, fontdb)?;
                 }
             }
             _ => {}
         }
 
-        child.subroots(|subroot| fill_fonts(subroot, ctx, fontdb));
+        let mut result = Ok(());
+        child.subroots(|subroot| {
+            result = result.and(fill_fonts(subroot, ctx, fontdb));
+        });
+        result?;
     }
+
+    Ok(())
 }
diff --git a/src/util/context.rs b/src/util/context.rs
index db910384..2cf330f9 100644
--- a/src/util/context.rs
+++ b/src/util/context.rs
@@ -30,7 +30,7 @@ impl Context {
     pub fn new(
         #[allow(unused_variables)] tree: &Tree,
         options: ConversionOptions,
-    ) -> Self {
+    ) -> Result<Self> {
         #[allow(unused_mut)]
         let mut ctx = Self {
             ref_allocator: RefAllocator::new(),
@@ -43,10 +43,10 @@ impl Context {
 
         #[cfg(feature = "text")]
         if options.embed_text {
-            text::fill_fonts(tree.root(), &mut ctx, tree.fontdb().as_ref());
+            text::fill_fonts(tree.root(), &mut ctx, tree.fontdb().as_ref())?;
         }
 
-        ctx
+        Ok(ctx)
     }
 
     /// Allocate a new reference.
diff --git a/src/util/helper.rs b/src/util/helper.rs
index a5ffcf87..b28d053e 100644
--- a/src/util/helper.rs
+++ b/src/util/helper.rs
@@ -3,6 +3,7 @@ use pdf_writer::{Content, Name, Rect};
 use usvg::{LineCap, LineJoin, NonZeroRect, Transform};
 
 use crate::render::gradient::Stop;
+use crate::{ConversionError, Result};
 
 /// Extension trait to convert [Colors](usvg::Color) into PDF colors.
 pub trait ColorExt {
@@ -48,6 +49,21 @@ impl RectExt for NonZeroRect {
     }
 }
 
+/// Extension trait for [Content].
+pub trait ContentExt {
+    fn save_state_checked(&mut self) -> Result<()>;
+}
+
+impl ContentExt for Content {
+    fn save_state_checked(&mut self) -> Result<()> {
+        self.save_state();
+        if self.state_nesting_depth() > 28 {
+            return Err(ConversionError::TooMuchNesting);
+        }
+        Ok(())
+    }
+}
+
 /// Extension trait to turn a [`usvg` BlendMode](usvg::BlendMode) into a [PDF Blendmode](BlendMode)
 pub trait BlendModeExt {
     fn to_pdf_blend_mode(&self) -> BlendMode;