diff --git a/Cargo.toml b/Cargo.toml
index 24b9ff697..1b5300cf7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "backtrace"
-version = "0.3.44"
+version = "0.3.45"
 authors = ["The Rust Project Developers"]
 license = "MIT/Apache-2.0"
 readme = "README.md"
@@ -21,7 +21,7 @@ exclude = ['crates/without_debuginfo']
 [dependencies]
 cfg-if = "0.1.10"
 rustc-demangle = "0.1.4"
-backtrace-sys = { path = "crates/backtrace-sys", version = "0.1.32", optional = true }
+backtrace-sys = { path = "crates/backtrace-sys", version = "0.1.33", optional = true, default_features = false }
 libc = { version = "0.2.45", default-features = false }
 core = { version = "1.0.0", optional = true, package = 'rustc-std-workspace-core' }
 compiler_builtins = { version = '0.1.2', optional = true }
@@ -37,7 +37,7 @@ cpp_demangle = { default-features = false, version = "0.2.3", optional = true }
 addr2line = { version = "0.11.0", optional = true, default-features = false, features = ['std'] }
 findshlibs = { version = "0.5.0", optional = true }
 memmap = { version = "0.7.0", optional = true }
-goblin = { version = "0.1.3", optional = true, default-features = false, features = ['elf32', 'elf64', 'mach32', 'mach64', 'pe32', 'pe64', 'std'] }
+goblin = { version = "0.2", optional = true, default-features = false, features = ['elf32', 'elf64', 'mach32', 'mach64', 'pe32', 'pe64', 'std'] }
 
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3.3", optional = true }
@@ -94,7 +94,7 @@ kernel32 = []
 #   the moment, this is only possible when targetting Linux, since macOS
 #   splits DWARF out into a separate object file. Enabling this feature
 #   means one less C dependency.
-libbacktrace = ["backtrace-sys"]
+libbacktrace = ["backtrace-sys/backtrace-sys"]
 dladdr = []
 coresymbolication = []
 gimli-symbolize = ["addr2line", "findshlibs", "memmap", "goblin"]
diff --git a/crates/backtrace-sys/Cargo.toml b/crates/backtrace-sys/Cargo.toml
index 5245d6b1f..5ed8b1930 100644
--- a/crates/backtrace-sys/Cargo.toml
+++ b/crates/backtrace-sys/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "backtrace-sys"
-version = "0.1.32"
+version = "0.1.33"
 authors = ["Alex Crichton <alex@alexcrichton.com>"]
 build = "build.rs"
 license = "MIT/Apache-2.0"
@@ -20,4 +20,8 @@ compiler_builtins = { version = '0.1.2', optional = true }
 cc = "1.0.37"
 
 [features]
+default = ["backtrace-sys"]
+
+# Without this feature, this crate does nothing.
+backtrace-sys = []
 rustc-dep-of-std = ['core', 'compiler_builtins']
diff --git a/crates/backtrace-sys/build.rs b/crates/backtrace-sys/build.rs
index 98ab6be05..564f23a91 100644
--- a/crates/backtrace-sys/build.rs
+++ b/crates/backtrace-sys/build.rs
@@ -7,7 +7,8 @@ use std::path::PathBuf;
 fn main() {
     let target = env::var("TARGET").unwrap();
 
-    if target.contains("msvc") || // libbacktrace isn't used on MSVC windows
+    if !cfg!(feature = "backtrace-sys") || // without this feature, this crate does nothing
+        target.contains("msvc") || // libbacktrace isn't used on MSVC windows
         target.contains("emscripten") || // no way this will ever compile for emscripten
         target.contains("cloudabi") ||
         target.contains("hermit") ||
@@ -30,10 +31,17 @@ fn main() {
         .file("src/libbacktrace/dwarf.c")
         .file("src/libbacktrace/fileline.c")
         .file("src/libbacktrace/posix.c")
-        .file("src/libbacktrace/read.c")
         .file("src/libbacktrace/sort.c")
         .file("src/libbacktrace/state.c");
 
+    // `mmap` does not exist on Windows, so we use
+    // the less efficient `read`-based code.
+    if target.contains("windows") {
+        build.file("src/libbacktrace/read.c");
+    } else {
+        build.file("src/libbacktrace/mmapio.c");
+    }
+
     // No need to have any symbols reexported form shared objects
     build.flag("-fvisibility=hidden");
 
diff --git a/src/symbolize/gimli.rs b/src/symbolize/gimli.rs
index 1529a90a0..03124a350 100644
--- a/src/symbolize/gimli.rs
+++ b/src/symbolize/gimli.rs
@@ -158,6 +158,7 @@ cfg_if::cfg_if! {
         struct Object<'a> {
             macho: MachO<'a>,
             dwarf: Option<usize>,
+            syms: Vec<(&'a str, u64)>,
         }
 
         impl<'a> Object<'a> {
@@ -171,7 +172,16 @@ cfg_if::cfg_if! {
                     .enumerate()
                     .find(|(_, segment)| segment.name().ok() == Some("__DWARF"))
                     .map(|p| p.0);
-                Some(Object { macho, dwarf })
+                let mut syms = Vec::new();
+                if let Some(s) = &macho.symbols {
+                    syms = s.iter()
+                        .filter_map(|e| e.ok())
+                        .filter(|(name, nlist)| name.len() > 0 && !nlist.is_undefined())
+                        .map(|(name, nlist)| (name, nlist.n_value))
+                        .collect();
+                }
+                syms.sort_unstable_by_key(|(_, addr)| *addr);
+                Some(Object { macho, dwarf, syms })
             }
 
             fn section(&self, name: &str) -> Option<&'a [u8]> {
@@ -194,12 +204,13 @@ cfg_if::cfg_if! {
                     .map(|p| p.1)
             }
 
-            fn search_symtab<'b>(&'b self, _addr: u64) -> Option<&'b [u8]> {
-                // So far it seems that we don't need to implement this. Maybe
-                // `dladdr` on OSX has us covered? Maybe there's not much in the
-                // symbol table? In any case our relevant tests are passing
-                // without this being implemented, so let's skip it for now.
-                None
+            fn search_symtab<'b>(&'b self, addr: u64) -> Option<&'b [u8]> {
+                let i = match self.syms.binary_search_by_key(&addr, |(_, addr)| *addr) {
+                    Ok(i) => i,
+                    Err(i) => i.checked_sub(1)?,
+                };
+                let (sym, _addr) = self.syms.get(i)?;
+                Some(sym.as_bytes())
             }
         }
     } else {