diff --git a/src/client/proxy/matcher.rs b/src/client/proxy/matcher.rs
index d0b71981..3ec90fd6 100644
--- a/src/client/proxy/matcher.rs
+++ b/src/client/proxy/matcher.rs
@@ -657,6 +657,41 @@ mod mac {
 #[cfg(feature = "client-proxy-system")]
 #[cfg(windows)]
 mod win {
+    fn ipv4_wildcard_to_cidr(value: &str) -> Option<String> {
+        let parts = value.split('.').collect::<Vec<_>>();
+        let wildcard = parts.iter().position(|part| *part == "*")?;
+
+        if wildcard == 0 || wildcard > 3 || parts[wildcard..].iter().any(|part| *part != "*") {
+            return None;
+        }
+
+        let mut octets = [0; 4];
+        for (index, part) in parts[..wildcard].iter().enumerate() {
+            octets[index] = part.parse().ok()?;
+        }
+
+        Some(format!(
+            "{}.{}.{}.{}/{}",
+            octets[0],
+            octets[1],
+            octets[2],
+            octets[3],
+            wildcard * 8
+        ))
+    }
+
+    pub(super) fn normalize_proxy_override(value: &str) -> String {
+        value
+            .split(';')
+            .map(|entry| {
+                let entry = entry.trim();
+                ipv4_wildcard_to_cidr(entry).unwrap_or_else(|| entry.to_string())
+            })
+            .collect::<Vec<_>>()
+            .join(",")
+            .replace("*.", "")
+    }
+
     pub(super) fn with_system(builder: &mut super::Builder) {
         let settings = if let Ok(settings) = windows_registry::CURRENT_USER
             .open("Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings")
@@ -681,12 +716,7 @@ mod win {
 
         if builder.no.is_empty() {
             if let Ok(val) = settings.get_string("ProxyOverride") {
-                builder.no = val
-                    .split(';')
-                    .map(|s| s.trim())
-                    .collect::<Vec<&str>>()
-                    .join(",")
-                    .replace("*.", "");
+                builder.no = normalize_proxy_override(&val);
             }
         }
     }
@@ -778,6 +808,25 @@ mod tests {
         }
     }
 
+    #[cfg(all(feature = "client-proxy-system", windows))]
+    #[test]
+    fn test_windows_proxy_override_ip_wildcard() {
+        let normalized =
+            win::normalize_proxy_override("127.*; 10.*.*.*; 192.168.*; 192.168.1.*; *.example.com");
+        let no_proxy = NoProxy::from_string(&normalized);
+
+        assert!(no_proxy.contains("127.0.0.1"));
+        assert!(no_proxy.contains("10.12.34.56"));
+        assert!(no_proxy.contains("192.168.42.1"));
+        assert!(no_proxy.contains("192.168.1.42"));
+        assert!(no_proxy.contains("www.example.com"));
+        assert!(!no_proxy.contains("128.0.0.1"));
+        assert!(!no_proxy.contains("192.169.42.1"));
+
+        let subnet = NoProxy::from_string(&win::normalize_proxy_override("192.168.1.*"));
+        assert!(!subnet.contains("192.168.2.42"));
+    }
+
     macro_rules! p {
         ($($n:ident = $v:expr,)*) => ({Builder {
             $($n: $v.into(),)*