diff --git a/crates/text/build.rs b/crates/text/build.rs
index 73c952fa..25544a3a 100644
--- a/crates/text/build.rs
+++ b/crates/text/build.rs
@@ -51,6 +51,12 @@ fn main() {
     }
     let src = format!("pub static CRAFT_FONTS: &[CraftFont] = &[\n{fonts}];\npub static WEB_FONTS: &[WebFont] = &[\n{web}];\n");
     let out = PathBuf::from(std::env::var_os("OUT_DIR").unwrap_or_default()).join("craft_fonts.rs");
+    // Unchanged output keeps its mtime. Rewritten just before this crate compiles, it can read as
+    // newer than that compile where cargo's recorded times lose their sub-second part (ecryptfs
+    // home directories), and the next build would compile this crate and everything above it again.
+    if std::fs::read_to_string(&out).is_ok_and(|old| old == src) {
+        return;
+    }
     if let Err(e) = std::fs::write(&out, src) {
         println!("cargo::error=writing {}: {e}", out.display());
     }
diff --git a/crates/ui-egui/build.rs b/crates/ui-egui/build.rs
index f40007fb..22fa00b2 100644
--- a/crates/ui-egui/build.rs
+++ b/crates/ui-egui/build.rs
@@ -21,7 +21,13 @@ fn main() {
     let people = read(&dir.join("people.toml"), "contributors are shown by username only", |t| t.parse::<toml::Table>().map_err(|e| e.to_string()))
         .unwrap_or_default();
     let out = std::path::PathBuf::from(std::env::var_os("OUT_DIR").unwrap_or_default()).join("credits.rs");
-    if let Err(e) = std::fs::write(&out, generate(&json, &people)) {
+    let src = generate(&json, &people);
+    // Unchanged output keeps its mtime, so the next build doesn't compile this crate again
+    // (see crates/text/build.rs).
+    if std::fs::read_to_string(&out).is_ok_and(|old| old == src) {
+        return;
+    }
+    if let Err(e) = std::fs::write(&out, src) {
         println!("cargo::warning=writing {}: {e}", out.display());
     }
 }