diff --git a/crates/numfmt/src/lib.rs b/crates/numfmt/src/lib.rs
index 674e844..9fcc146 100644
--- a/crates/numfmt/src/lib.rs
+++ b/crates/numfmt/src/lib.rs
@@ -261,7 +261,8 @@ impl NumberFormat {
         let Some(mut out) = out else {
             return (Formatted { text: OVERFLOW.into(), color: sec.color, fill: None, numeric: true }, true);
         };
-        if minus && sec.kind != SecKind::Text {
+        // Excel drops the minus sign when the first section shows a negative number as all zeros.
+        if minus && sec.kind != SecKind::Text && !out.zero {
             out.prepend("-");
         }
         (Formatted { text: out.text, color: sec.color, fill: out.fill, numeric: true }, false)
diff --git a/crates/numfmt/src/render.rs b/crates/numfmt/src/render.rs
index 7befe59..d6c7d67 100644
--- a/crates/numfmt/src/render.rs
+++ b/crates/numfmt/src/render.rs
@@ -11,6 +11,8 @@ use crate::parse::{DatePart, Section, Tok};
 pub(crate) struct Out {
     pub text: String,
     pub fill: Option<(char, usize)>,
+    /// True when every digit shown is zero (a number section that rounded to zero).
+    pub zero: bool,
 }
 
 impl Out {
@@ -247,6 +249,7 @@ pub(crate) fn render_number(sec: &Section, v: f64) -> Out {
     let mut pieces: Vec<String> = vec![String::new(); n];
     let mut before: Vec<String> = vec![String::new(); n + 1];
     let mut lits: Vec<Option<String>> = Vec::new();
+    let mut zero = false;
     if sec.fraction {
         lits = vec![None; n];
         render_fraction(sec, x, &mut pieces, &mut lits);
@@ -310,6 +313,7 @@ pub(crate) fn render_number(sec: &Section, v: f64) -> Out {
         } else {
             fixed(x, frac_idx.len())
         };
+        zero = int_s.chars().chain(frac_s.chars()).all(|c| c == '0');
         fill_int(toks, &int_idx, &int_s, sec.thousands, false, &mut pieces);
         if int_idx.is_empty()
             && !int_s.is_empty()
@@ -338,6 +342,7 @@ pub(crate) fn render_number(sec: &Section, v: f64) -> Out {
             _ => out.push(pieces.get(i).map(String::as_str).unwrap_or("")),
         }
     }
+    out.zero = zero;
     out
 }
 
diff --git a/crates/numfmt/src/tests.rs b/crates/numfmt/src/tests.rs
index 6c2306c..1cd88ef 100644
--- a/crates/numfmt/src/tests.rs
+++ b/crates/numfmt/src/tests.rs
@@ -24,7 +24,7 @@ fn numbers() {
     assert_eq!(f("0", -2.5), "-3");
     assert_eq!(f("0.00", 2.675), "2.68");
     assert_eq!(f("0.00", 1.005), "1.01");
-    assert_eq!(f("0.0", -0.04), "-0.0");
+    assert_eq!(f("0.0", -0.04), "0.0");
     assert_eq!(f("00000", 123.0), "00123");
     assert_eq!(f("000-00-0000", 123456789.0), "123-45-6789");
     assert_eq!(f("#.##", 0.5), ".5");
@@ -105,6 +105,29 @@ fn scientific() {
     assert_eq!(f("0.00E+00", -12345.0), "-1.23E+04");
 }
 
+/// A negative number that rounds to zero in the first section shows no minus sign; a negative
+/// section of its own keeps its text (observed Excel results).
+#[test]
+fn negative_rounding_to_zero_drops_the_sign() {
+    let cases: &[(&str, f64, &str)] = &[
+        ("0.00", -0.0033, "0.00"),
+        ("0.00", -2.89e-9, "0.00"),
+        ("0.00", -0.005, "-0.01"),
+        ("0", -0.4, "0"),
+        ("0", -0.5, "-1"),
+        ("0.0", -0.004, "0.0"),
+        ("#,##0.00", -0.004, "0.00"),
+        ("0.00%", -2.89e-9, "0.00%"),
+        ("0.00%", -0.0033, "-0.33%"),
+        ("0.00;(0.00)", -0.0033, "(0.00)"),
+        ("0.00;-0.00;\"zero\"", -0.0033, "-0.00"),
+        ("0.00E+00", -2.89e-9, "-2.89E-09"),
+    ];
+    for &(code, n, want) in cases {
+        assert_eq!(f(code, n), want, "{code} with {n}");
+    }
+}
+
 #[test]
 fn fractions() {
     assert_eq!(f("# ?/?", 1.5), "1 1/2");
@@ -340,6 +363,8 @@ fn text_fn() {
     assert_eq!(text_function(&Value::Number(5.0), "", S), Ok("".into()));
     assert_eq!(text_function(&Value::Number(-1.0), "m/d/yyyy", S), Err(CellError::Value));
     assert_eq!(text_function(&Value::Bool(true), "0", S), Ok("TRUE".into()));
+    assert_eq!(text_function(&Value::Number(-0.0033), "0", S), Ok("0".into()));
+    assert_eq!(text_function(&Value::Number(-0.4), "0", S), Ok("0".into()));
     // Booleans go through the text section as TRUE/FALSE (observed Excel results).
     let cases: &[(bool, &str, &str)] = &[
         (true, ";;;@", "TRUE"),