diff --git a/Cargo.lock b/Cargo.lock
index adfd6cdc1..e98d10275 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -81,7 +81,7 @@ checksum = "366ffbaa4442f4684d91e2cd7c5ea7c4ed8add41959a31447066e279e432b618"
 [[package]]
 name = "acadrust"
 version = "0.5.5"
-source = "git+https://github.com/HakanSeven12/cadcodec.git?rev=5eea24cf35ba1739c22e982fc398ddb6c285def5#5eea24cf35ba1739c22e982fc398ddb6c285def5"
+source = "git+https://github.com/HakanSeven12/cadcodec.git?rev=de72d5c9d4a78d5dff7138bbc9a9b8fcdf7430ad#de72d5c9d4a78d5dff7138bbc9a9b8fcdf7430ad"
 dependencies = [
  "ahash 0.8.12",
  "anyhow",
@@ -896,7 +896,7 @@ checksum = "fc652a48c352aef3ea3aed32080501cf3ef6ed5da78602a020c991775b0aff04"
 [[package]]
 name = "cadkernel"
 version = "0.1.0"
-source = "git+https://github.com/HakanSeven12/cadkernel.git?rev=5f0cdffc0faa9db03346aa794e22285c365b5f7f#5f0cdffc0faa9db03346aa794e22285c365b5f7f"
+source = "git+https://github.com/HakanSeven12/cadkernel.git?rev=773070e4e5dcfcceddf9750a876bf67353642922#773070e4e5dcfcceddf9750a876bf67353642922"
 dependencies = [
  "acadrust",
  "cavalier_contours",
@@ -907,7 +907,7 @@ dependencies = [
 [[package]]
 name = "cadkernel-constraints"
 version = "0.1.0"
-source = "git+https://github.com/HakanSeven12/cadkernel.git?rev=5f0cdffc0faa9db03346aa794e22285c365b5f7f#5f0cdffc0faa9db03346aa794e22285c365b5f7f"
+source = "git+https://github.com/HakanSeven12/cadkernel.git?rev=773070e4e5dcfcceddf9750a876bf67353642922#773070e4e5dcfcceddf9750a876bf67353642922"
 dependencies = [
  "nalgebra",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index b01082514..78bdbd874 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -31,9 +31,9 @@ glam = { version = "0.33", features = ["bytemuck"] }
 rfd = "0.17"
 clap = { version = "4", features = ["derive", "string"] }
 env_logger = "0.11"
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "5eea24cf35ba1739c22e982fc398ddb6c285def5", features = ["serde"] }
-cadkernel = { git = "https://github.com/HakanSeven12/cadkernel.git", rev = "5f0cdffc0faa9db03346aa794e22285c365b5f7f", features = ["acis", "offset"] }
-cadkernel-constraints = { git = "https://github.com/HakanSeven12/cadkernel.git", rev = "5f0cdffc0faa9db03346aa794e22285c365b5f7f" }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "de72d5c9d4a78d5dff7138bbc9a9b8fcdf7430ad", features = ["serde"] }
+cadkernel = { git = "https://github.com/HakanSeven12/cadkernel.git", rev = "773070e4e5dcfcceddf9750a876bf67353642922", features = ["acis", "offset"] }
+cadkernel-constraints = { git = "https://github.com/HakanSeven12/cadkernel.git", rev = "773070e4e5dcfcceddf9750a876bf67353642922" }
 dwg-thumbnailer = { path = "crates/dwg-thumbnailer" }
 flate2 = "1"
 image = { version = "0.25", default-features = false, features = ["png", "jpeg", "bmp", "tiff"] }
diff --git a/crates/ocs_plugin_api/Cargo.toml b/crates/ocs_plugin_api/Cargo.toml
index 0687ff106..06b5319a6 100644
--- a/crates/ocs_plugin_api/Cargo.toml
+++ b/crates/ocs_plugin_api/Cargo.toml
@@ -14,7 +14,7 @@ serde = { version = "1", features = ["derive"] }
 # Pulled in only by the `host` feature, which adds the `acadrust`-typed
 # `HostApi` runtime surface. The default crate stays dependency-free so engine
 # crates and external tooling can depend on the manifest/ribbon contract cheaply.
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "5eea24cf35ba1739c22e982fc398ddb6c285def5", optional = true, features = ["serde"] }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "de72d5c9d4a78d5dff7138bbc9a9b8fcdf7430ad", optional = true, features = ["serde"] }
 
 # Runtime IPC and serialization (host feature only).
 interprocess = { version = "2", optional = true }
@@ -38,7 +38,7 @@ serde_json = "1"
 serde = { version = "1", features = ["derive"] }
 cargo-lock = "11"
 # acadrust is scanned at build time to generate the embedded type registry.
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "5eea24cf35ba1739c22e982fc398ddb6c285def5", features = ["serde"] }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "de72d5c9d4a78d5dff7138bbc9a9b8fcdf7430ad", features = ["serde"] }
 
 [dev-dependencies]
 serde_json = "1"
diff --git a/crates/ocs_web_worker/Cargo.toml b/crates/ocs_web_worker/Cargo.toml
index 6696d3ff4..2b1b72071 100644
--- a/crates/ocs_web_worker/Cargo.toml
+++ b/crates/ocs_web_worker/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "5eea24cf35ba1739c22e982fc398ddb6c285def5", features = ["serde"] }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "de72d5c9d4a78d5dff7138bbc9a9b8fcdf7430ad", features = ["serde"] }
 bincode = "1.3"
 serde = { version = "1", features = ["derive"] }
 console_error_panic_hook = "0.1"
diff --git a/crates/plugin-template-api2/Cargo.toml b/crates/plugin-template-api2/Cargo.toml
index 399a1f929..6630f38fa 100644
--- a/crates/plugin-template-api2/Cargo.toml
+++ b/crates/plugin-template-api2/Cargo.toml
@@ -10,4 +10,4 @@ crate-type = ["cdylib"]
 
 [dependencies]
 ocs_plugin_api = { path = "../ocs_plugin_api", features = ["host"] }
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "5eea24cf35ba1739c22e982fc398ddb6c285def5", features = ["serde"] }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "de72d5c9d4a78d5dff7138bbc9a9b8fcdf7430ad", features = ["serde"] }
diff --git a/docs/plugin-template-v2/Cargo.toml b/docs/plugin-template-v2/Cargo.toml
index e5cbea928..e44f97abf 100644
--- a/docs/plugin-template-v2/Cargo.toml
+++ b/docs/plugin-template-v2/Cargo.toml
@@ -12,4 +12,4 @@ crate-type = ["cdylib"]
 
 [dependencies]
 ocs_plugin_api = { path = "../../crates/ocs_plugin_api", features = ["host"] }
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "5eea24cf35ba1739c22e982fc398ddb6c285def5" }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "de72d5c9d4a78d5dff7138bbc9a9b8fcdf7430ad" }
diff --git a/src/entities/common.rs b/src/entities/common.rs
index c31b8e25e..bbb215f7b 100644
--- a/src/entities/common.rs
+++ b/src/entities/common.rs
@@ -110,7 +110,12 @@ pub fn format_length(value: f64) -> String {
 /// rotation leaves coordinates like -1e-15 behind, which read as `-0.0000`.
 fn without_negative_zero(text: String) -> String {
     match text.strip_prefix('-') {
-        Some(rest) if !rest.chars().any(|c| matches!(c, '1'..='9')) => rest.to_string(),
+        Some(rest)
+            if rest.chars().any(|c| c.is_ascii_digit())
+                && !rest.chars().any(|c| matches!(c, '1'..='9')) =>
+        {
+            rest.to_string()
+        }
         _ => text,
     }
 }
@@ -1276,4 +1281,10 @@ mod negative_zero_format_tests {
         assert_eq!(angle(0, 0, -45f64.to_radians()), "-45°");
         assert_eq!(angle(1, 1, -0.0001f64.to_radians()), "-0d0'0.4\"");
     }
+
+    #[test]
+    fn a_negative_infinite_value_keeps_its_sign() {
+        assert_eq!(length(2, 4, f64::NEG_INFINITY), "-inf");
+        assert_eq!(angle(0, 0, f64::NEG_INFINITY), "-inf°");
+    }
 }
diff --git a/src/io/obj.rs b/src/io/obj.rs
index 4b1a5e157..06231c838 100644
--- a/src/io/obj.rs
+++ b/src/io/obj.rs
@@ -75,7 +75,12 @@ pub fn parse_obj(src: &str, color: [f32; 4]) -> Option<MeshModel> {
     for (vi, (pos_i, norm_i)) in face_verts.iter().enumerate() {
         let pos = *positions.get(*pos_i).unwrap_or(&[0.0; 3]);
         verts.push(pos);
-        let norm = norm_i.and_then(|ni| normals_raw.get(ni).copied());
+        let norm = norm_i
+            .and_then(|ni| normals_raw.get(ni).copied())
+            .filter(|n| {
+                n.iter().all(|value| value.is_finite())
+                    && n.iter().map(|value| value * value).sum::<f32>() > 1e-12
+            });
         has_normal.push(norm.is_some());
         norms.push(norm.unwrap_or([0.0, 0.0, 0.0]));
         indices.push(vi as u32);
@@ -153,6 +158,13 @@ mod tests {
         assert_normals(&mesh.normals, [0.0, 0.0, 1.0]);
     }
 
+    #[test]
+    fn a_zero_normal_gets_the_face_normal() {
+        let src = format!("{SQUARE}vn 0 0 0\nf 1//1 2//1 3//1\n");
+        let mesh = parse_obj(&src, COLOR).expect("mesh");
+        assert_normals(&mesh.normals, [0.0, 0.0, 1.0]);
+    }
+
     /// Only the vertex with a bad index is filled; its neighbours keep theirs.
     #[test]
     fn only_the_vertex_without_a_normal_is_filled() {