PyO3 · ognevny · Jun 26, 2026
diff --git a/noxfile.py b/noxfile.py
@@ -1363,16 +1363,27 @@ def _check_raw_dylib_macro(session: nox.Session):
     max_minor = int(max_version.split(".")[1])
 
     # Build the set of DLL names that default_lib_name_windows can produce
-    expected_dlls = {"python3", "python3_d"}
+    expected_dlls = {
+        "python3",
+        "python3_d",
+        "libpython3",
+        "libpython3_d",
+    }
     for minor in range(min_minor, max_minor + 1):
         expected_dlls.add(f"python3{minor}")
         expected_dlls.add(f"python3{minor}_d")
+        expected_dlls.add(f"libpython3.{minor}")
+        expected_dlls.add(f"libpython3.{minor}_d")
         if minor >= 13:
             expected_dlls.add(f"python3{minor}t")
             expected_dlls.add(f"python3{minor}t_d")
+            expected_dlls.add(f"libpython3.{minor}t")
+            expected_dlls.add(f"libpython3.{minor}t_d")
         if minor >= 15:
             expected_dlls.add("python3t")
             expected_dlls.add("python3t_d")
+            expected_dlls.add("libpython3t")
+            expected_dlls.add("libpython3t_d")
 
     # PyPy DLL names (libpypy3.X-c.dll)
     pypy_min, pypy_max = _parse_supported_interpreter_version("pypy")
@@ -1383,7 +1394,7 @@ def _check_raw_dylib_macro(session: nox.Session):
 
     # Parse the DLL name list in the extern_libpython!(@impl ...) invocation
     lib_rs = (PYO3_DIR / "pyo3-ffi" / "src" / "impl_" / "macros.rs").read_text()
-    found_dlls = set(re.findall(r'"((?:python|libpypy)[^"]+)"', lib_rs))
+    found_dlls = set(re.findall(r'"((?:python|libpython|libpypy)[^"]+)"', lib_rs))
 
     missing = expected_dlls - found_dlls
     extra = found_dlls - expected_dlls

diff --git a/pyo3-build-config/src/impl_.rs b/pyo3-build-config/src/impl_.rs
@@ -2302,7 +2302,12 @@ const WINDOWS_STABLE_ABI_DEBUG_LIB_NAME: &str = "python3_d";
 #[allow(dead_code)]
 fn default_lib_name_for_target(abi: PythonAbi, target: &Triple) -> String {
     if target.operating_system == OperatingSystem::Windows {
-        default_lib_name_windows(abi, false, false).unwrap()
+        default_lib_name_windows(
+            abi,
+            matches!(target.environment, Environment::Gnu | Environment::GnuLlvm),
+            false,
+        )
+        .unwrap()
     } else {
         default_lib_name_unix(
             abi,
@@ -2314,6 +2319,10 @@ fn default_lib_name_for_target(abi: PythonAbi, target: &Triple) -> String {
 }
 
 fn default_lib_name_windows(abi: PythonAbi, mingw: bool, debug: bool) -> Result<String> {
+    // set `lib` prefix for mingw, as its python abi library is shipped prefixed. also mingw
+    // library has the version separated by dot
+    let (lib_prefix, separator) = if mingw { ("lib", ".") } else { ("", "") };
+
     if abi.implementation.is_pypy() {
         // PyPy on Windows ships `libpypy3.X-c.dll` (e.g. `libpypy3.11-c.dll`),
         // not CPython's `pythonXY.dll`. With raw-dylib linking we need the real
@@ -2326,7 +2335,7 @@ fn default_lib_name_windows(abi: PythonAbi, mingw: bool, debug: bool) -> Result<
         // CPython bug: linking against python3_d.dll raises error
         // https://github.com/python/cpython/issues/101614
         Ok(format!(
-            "python{}{}_d",
+            "{lib_prefix}python{}{separator}{}_d",
             abi.version.major, abi.version.minor
         ))
     } else if abi.kind == PythonAbiKind::Stable(StableAbi::Abi3)
@@ -2340,34 +2349,43 @@ fn default_lib_name_windows(abi: PythonAbi, mingw: bool, debug: bool) -> Result<
         if abi.kind == PythonAbiKind::Stable(StableAbi::Abi3t) {
             lib_name = lib_name.replace("python3", "python3t");
         }
-        Ok(lib_name)
+        Ok(format!("{lib_prefix}{lib_name}"))
     } else if mingw {
         ensure!(
             !abi.kind.is_free_threaded(),
             "MinGW free-threaded builds are not currently tested or supported"
         );
         // https://packages.msys2.org/base/mingw-w64-python
-        Ok(format!("python{}.{}", abi.version.major, abi.version.minor))
+        Ok(format!(
+            "{lib_prefix}python{}.{}",
+            abi.version.major, abi.version.minor
+        ))
     } else if abi.kind().is_free_threaded() {
         #[expect(deprecated, reason = "using constant internally")]
         {
             ensure!(abi.version() >= PythonVersion::PY313, "Cannot compile extensions for the free-threaded build on Python versions earlier than 3.13, found {}.{}", abi.version.major, abi.version.minor);
         }
         if debug {
             Ok(format!(
-                "python{}{}t_d",
+                "{lib_prefix}python{}{separator}{}t_d",
                 abi.version.major, abi.version.minor
             ))
         } else {
-            Ok(format!("python{}{}t", abi.version.major, abi.version.minor))
+            Ok(format!(
+                "{lib_prefix}python{}{separator}{}t",
+                abi.version.major, abi.version.minor
+            ))
         }
     } else if debug {
         Ok(format!(
-            "python{}{}_d",
+            "{lib_prefix}python{}{separator}{}_d",
             abi.version.major, abi.version.minor
         ))
     } else {
-        Ok(format!("python{}{}", abi.version.major, abi.version.minor))
+        Ok(format!(
+            "{lib_prefix}python{}{separator}{}",
+            abi.version.major, abi.version.minor
+        ))
     }
 }
 
@@ -3091,7 +3109,7 @@ mod tests {
         let implementation = PythonImplementation::CPython;
         let version = PythonVersion::PY39;
         let config = InterpreterConfigBuilder::new(implementation, version)
-            .lib_name("python39".to_string())
+            .lib_name("libpython3.9".to_string())
             .lib_dir("/usr/lib/mingw".to_string())
             .finalize()
             .unwrap();
@@ -3290,7 +3308,7 @@ mod tests {
                 false,
             )
             .unwrap(),
-            "python3.9",
+            "libpython3.9",
         );
         assert_eq!(
             super::default_lib_name_windows(
@@ -3302,7 +3320,7 @@ mod tests {
                 false,
             )
             .unwrap(),
-            "python3",
+            "libpython3",
         );
         assert_eq!(
             super::default_lib_name_windows(

diff --git a/pyo3-build-config/src/lib.rs b/pyo3-build-config/src/lib.rs
@@ -171,13 +171,21 @@ pub fn print_expected_cfgs() {
         "python3_d".to_string(),
         "python3t".to_string(),
         "python3t_d".to_string(),
+        "libpython3".to_string(),
+        "libpython3_d".to_string(),
+        "libpython3t".to_string(),
+        "libpython3t_d".to_string(),
     ];
     for i in impl_::MINIMUM_SUPPORTED_VERSION.minor..=impl_::STABLE_ABI_MAX_MINOR + 1 {
         dll_names.push(format!("python3{i}"));
         dll_names.push(format!("python3{i}_d"));
+        dll_names.push(format!("libpython3.{i}"));
+        dll_names.push(format!("libpython3.{i}_d"));
         if i >= 13 {
             dll_names.push(format!("python3{i}t"));
             dll_names.push(format!("python3{i}t_d"));
+            dll_names.push(format!("libpython3.{i}t"));
+            dll_names.push(format!("libpython3.{i}t_d"));
         }
     }
     // PyPy DLL names (libpypy3.X-c.dll)

diff --git a/pyo3-ffi/src/impl_/macros.rs b/pyo3-ffi/src/impl_/macros.rs
@@ -257,21 +257,21 @@ macro_rules! extern_libpython {
     ($abi:literal { $($body:tt)* }) => {
         extern_libpython!(@impl $abi { $($body)* }
             // abi3
-            "python3", "python3_d",
+            "python3", "python3_d", "libpython3", "libpython3_d",
             // abi3t
-            "python3t", "python3t_d",
+            "python3t", "python3t_d", "libpython3t", "libpython3t_d",
             // Python 3.9 - 3.15
-            "python39", "python39_d",
-            "python310", "python310_d",
-            "python311", "python311_d",
-            "python312", "python312_d",
-            "python313", "python313_d",
-            "python314", "python314_d",
-            "python315", "python315_d",
+            "python39", "python39_d", "libpython3.9", "libpython3.9_d",
+            "python310", "python310_d", "libpython3.10", "libpython3.10_d",
+            "python311", "python311_d", "libpython3.11", "libpython3.11_d",
+            "python312", "python312_d", "libpython3.12", "libpython3.12_d",
+            "python313", "python313_d", "libpython3.13", "libpython3.13_d",
+            "python314", "python314_d", "libpython3.14", "libpython3.14_d",
+            "python315", "python315_d", "libpython3.15", "libpython3.15_d",
             // free-threaded builds (3.13+)
-            "python313t", "python313t_d",
-            "python314t", "python314t_d",
-            "python315t", "python315t_d",
+            "python313t", "python313t_d", "libpython3.13t", "libpython3.13t_d",
+            "python314t", "python314t_d", "libpython3.14t", "libpython3.14t_d",
+            "python315t", "python315t_d", "libpython3.15t", "libpython3.15t_d",
             // PyPy (DLL is libpypy3.X-c.dll, not pythonXY.dll)
             "libpypy3.11-c",
         );