diff --git a/Cargo-minimal.lock b/Cargo-minimal.lock
index 1b19231fe..16c7e5987 100644
--- a/Cargo-minimal.lock
+++ b/Cargo-minimal.lock
@@ -95,6 +95,9 @@ dependencies = [
 [[package]]
 name = "bitcoin-io"
 version = "0.1.2"
+dependencies = [
+ "bitcoin-internals",
+]
 
 [[package]]
 name = "bitcoin-primitives"
diff --git a/Cargo-recent.lock b/Cargo-recent.lock
index dc727fe4b..fb2340a80 100644
--- a/Cargo-recent.lock
+++ b/Cargo-recent.lock
@@ -94,6 +94,9 @@ dependencies = [
 [[package]]
 name = "bitcoin-io"
 version = "0.1.2"
+dependencies = [
+ "bitcoin-internals",
+]
 
 [[package]]
 name = "bitcoin-primitives"
diff --git a/bitcoin/build.rs b/bitcoin/build.rs
deleted file mode 100644
index 2b741ca0d..000000000
--- a/bitcoin/build.rs
+++ /dev/null
@@ -1,37 +0,0 @@
-fn main() {
-    let rustc = std::env::var_os("RUSTC");
-    let rustc = rustc.as_ref().map(std::path::Path::new).unwrap_or_else(|| "rustc".as_ref());
-    let output = std::process::Command::new(rustc)
-        .arg("--version")
-        .output()
-        .unwrap_or_else(|error| panic!("failed to run `{:?} --version`: {:?}", rustc, error));
-    assert!(output.status.success(), "{:?} -- version returned non-zero exit code", rustc);
-    let stdout = String::from_utf8(output.stdout).expect("rustc produced non-UTF-8 output");
-    let version_prefix = "rustc ";
-    if !stdout.starts_with(version_prefix) {
-        panic!("unexpected rustc output: {}", stdout);
-    }
-
-    let version = &stdout[version_prefix.len()..];
-    let end = version.find(&[' ', '-'] as &[_]).unwrap_or(version.len());
-    let version = &version[..end];
-    let mut version_components = version.split('.');
-    let major = version_components.next().unwrap();
-    assert_eq!(major, "1", "unexpected Rust major version");
-    let minor = version_components
-        .next()
-        .unwrap_or("0")
-        .parse::<u64>()
-        .expect("invalid Rust minor version");
-
-    let msrv = std::env::var("CARGO_PKG_RUST_VERSION").unwrap();
-    let mut msrv = msrv.split(".");
-    let msrv_major = msrv.next().unwrap();
-    assert_eq!(msrv_major, "1", "unexpected Rust major version");
-    let msrv_minor = msrv.next().unwrap().parse::<u64>().unwrap();
-
-    // print cfg for all interesting versions less than or equal to minor
-    for version in msrv_minor..=minor {
-        println!("cargo:rustc-cfg=rust_v_1_{}", version);
-    }
-}
diff --git a/internals/Cargo.toml b/internals/Cargo.toml
index 7e46aa6bf..f3994febd 100644
--- a/internals/Cargo.toml
+++ b/internals/Cargo.toml
@@ -34,4 +34,4 @@ all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 
 [lints.rust]
-unexpected_cfgs = { level = "deny", check-cfg = ['cfg(rust_v_1_64)'] }
+unexpected_cfgs = { level = "deny" }
diff --git a/internals/build.rs b/internals/build.rs
index 2b741ca0d..b055def60 100644
--- a/internals/build.rs
+++ b/internals/build.rs
@@ -1,3 +1,7 @@
+const MAX_USED_VERSION: u64 = 80;
+
+use std::io;
+
 fn main() {
     let rustc = std::env::var_os("RUSTC");
     let rustc = rustc.as_ref().map(std::path::Path::new).unwrap_or_else(|| "rustc".as_ref());
@@ -30,8 +34,45 @@ fn main() {
     assert_eq!(msrv_major, "1", "unexpected Rust major version");
     let msrv_minor = msrv.next().unwrap().parse::<u64>().unwrap();
 
-    // print cfg for all interesting versions less than or equal to minor
-    for version in msrv_minor..=minor {
-        println!("cargo:rustc-cfg=rust_v_1_{}", version);
-    }
+    let out_dir = std::env::var_os("OUT_DIR").expect("missing OUT_DIR env var");
+    let out_dir = std::path::PathBuf::from(out_dir);
+    let macro_file = std::fs::File::create(out_dir.join("rust_version.rs")).expect("failed to create rust_version.rs");
+    let macro_file = io::BufWriter::new(macro_file);
+    write_macro(macro_file, msrv_minor, minor).expect("failed to write to rust_version.rs");
+}
+
+fn write_macro(mut macro_file: impl io::Write, msrv_minor: u64, minor: u64) -> io::Result<()> {
+    writeln!(macro_file, "/// Expands code based on Rust version this is compiled under.")?;
+    writeln!(macro_file, "///")?;
+    writeln!(macro_file, "/// Example:")?;
+    writeln!(macro_file, "/// ```")?;
+    writeln!(macro_file, "/// bitcoin_internals::rust_version! {{")?;
+    writeln!(macro_file, "///     if >= 1.70 {{")?;
+    writeln!(macro_file, "///         println!(\"This is Rust 1.70+\");")?;
+    writeln!(macro_file, "///     }} else {{")?;
+    writeln!(macro_file, "///         println!(\"This is Rust < 1.70\");")?;
+    writeln!(macro_file, "///     }}")?;
+    writeln!(macro_file, "/// }}")?;
+    writeln!(macro_file, "/// ```")?;
+    writeln!(macro_file, "///")?;
+    writeln!(macro_file, "/// The `else` branch is optional.")?;
+    writeln!(macro_file, "/// Currently only the `>=` operator is supported.")?;
+    writeln!(macro_file, "#[macro_export]")?;
+    writeln!(macro_file, "macro_rules! rust_version {{")?;
+    for version in msrv_minor..=minor {
+        writeln!(macro_file, "    (if >= 1.{} {{ $($if_yes:tt)* }} $(else {{ $($if_no:tt)* }})?) => {{", version)?;
+        writeln!(macro_file, "        $($if_yes)*")?;
+        writeln!(macro_file, "    }};")?;
+    }
+    for version in (minor + 1)..(MAX_USED_VERSION + 1) {
+        writeln!(macro_file, "    (if >= 1.{} {{ $($if_yes:tt)* }} $(else {{ $($if_no:tt)* }})?) => {{", version)?;
+        writeln!(macro_file, "        $($($if_no)*)?")?;
+        writeln!(macro_file, "    }};")?;
+    }
+    writeln!(macro_file, "    (if >= $unknown:tt $($rest:tt)*) => {{")?;
+    writeln!(macro_file, "        compile_error!(concat!(\"unknown Rust version \", stringify!($unknown)));")?;
+    writeln!(macro_file, "    }};")?;
+    writeln!(macro_file, "}}")?;
+    writeln!(macro_file, "pub use rust_version;")?;
+    macro_file.flush()
 }
diff --git a/internals/src/array_vec.rs b/internals/src/array_vec.rs
index bcce012d9..f75924ba1 100644
--- a/internals/src/array_vec.rs
+++ b/internals/src/array_vec.rs
@@ -46,7 +46,7 @@ mod safety_boundary {
         // from_raw_parts is const-unstable until 1.64
         cond_const! {
             /// Returns a reference to the underlying data.
-            pub const(in rust_v_1_64 = "1.64") fn as_slice(&self) -> &[T] {
+            pub const(in 1.64) fn as_slice(&self) -> &[T] {
                 let ptr = &self.data as *const _ as *const T;
                 unsafe { core::slice::from_raw_parts(ptr, self.len) }
             }
diff --git a/internals/src/const_tools.rs b/internals/src/const_tools.rs
index f475a23c7..bd4c72326 100644
--- a/internals/src/const_tools.rs
+++ b/internals/src/const_tools.rs
@@ -56,36 +56,34 @@ pub use concat_bytes_to_arr;
 #[macro_export]
 /// Enables const fn in specified Rust version
 macro_rules! cond_const {
-    ($($(#[$attr:meta])* $vis:vis const(in $ver:ident $(= $human_ver:literal)?) fn $name:ident$(<$($gen:tt)*>)?($($args:tt)*) $(-> $ret:ty)? $body:block)+ ) => {
+    ($($(#[$attr:meta])* $vis:vis const(in $version:tt) fn $name:ident$(<$($gen:tt)*>)?($($args:tt)*) $(-> $ret:ty)? $body:block)+ ) => {
         $(
-            #[cfg($ver)]
-            $(#[$attr])*
-            $(
-                #[doc = "\nNote: the function is only `const` in Rust "]
-                #[doc = $human_ver]
-                #[doc = "."]
-            )?
-            $vis const fn $name$(<$($gen)*>)?($($args)*) $(-> $ret)? $body
-
-            #[cfg(not($ver))]
-            $(#[$attr])*
-            $vis fn $name$(<$($gen)*>)?($($args)*) $(-> $ret)? $body
+            $crate::rust_version::rust_version! {
+                if >= $version {
+                    $(#[$attr])*
+                    #[doc = concat!("\nNote: the function is only `const` in Rust ", stringify!($version), ".")]
+                    $vis const fn $name$(<$($gen)*>)?($($args)*) $(-> $ret)? $body
+                } else {
+                    $(#[$attr])*
+                    #[doc = concat!("\nNote: the function is `const` in Rust ", stringify!($version), ".")]
+                    $vis fn $name$(<$($gen)*>)?($($args)*) $(-> $ret)? $body
+                }
+            }
         )+
     };
-    ($($(#[$attr:meta])* $vis:vis const(in $ver:ident $(= $human_ver:literal)?) unsafe fn $name:ident$(<$($gen:tt)*>)?($($args:tt)*) $(-> $ret:ty)? $body:block)+ ) => {
+    ($($(#[$attr:meta])* $vis:vis const(in $version:tt) unsafe fn $name:ident$(<$($gen:tt)*>)?($($args:tt)*) $(-> $ret:ty)? $body:block)+ ) => {
         $(
-            #[cfg($ver)]
-            $(#[$attr])*
-            $(
-                #[doc = "\nNote: the function is only `const` in Rust "]
-                #[doc = $human_ver]
-                #[doc = " and newer."]
-            )?
-            $vis const unsafe fn $name$(<$($gen)*>)?($($args)*) $(-> $ret)? $body
-
-            #[cfg(not($ver))]
-            $(#[$attr])*
-            $vis unsafe fn $name$(<$($gen)*>)?($($args)*) $(-> $ret)? $body
+            $crate::rust_version::rust_version! {
+                if >= $version {
+                    $(#[$attr])*
+                    #[doc = concat!("\nNote: the function is only `const` in Rust ", stringify!($version), ".")]
+                    $vis const unsafe fn $name$(<$($gen)*>)?($($args)*) $(-> $ret)? $body
+                } else {
+                    $(#[$attr])*
+                    #[doc = concat!("\nNote: the function is `const` in Rust ", stringify!($version), ".")]
+                    $vis unsafe fn $name$(<$($gen)*>)?($($args)*) $(-> $ret)? $body
+                }
+            }
         )+
     };
 }
diff --git a/internals/src/lib.rs b/internals/src/lib.rs
index fb93fd50e..6ecb272a9 100644
--- a/internals/src/lib.rs
+++ b/internals/src/lib.rs
@@ -27,6 +27,13 @@ pub extern crate serde_json;
 #[cfg(feature = "test-serde")]
 pub extern crate bincode;
 
+// The pub module is a workaround for strange error:
+// "macro-expanded `macro_export` macros from the current crate cannot be referred to by absolute paths"
+#[doc(hidden)]
+pub mod rust_version {
+    include!(concat!(env!("OUT_DIR"), "/rust_version.rs"));
+}
+
 pub mod array_vec;
 pub mod const_tools;
 pub mod error;
diff --git a/io/Cargo.toml b/io/Cargo.toml
index f6747bb3b..672eb5e2e 100644
--- a/io/Cargo.toml
+++ b/io/Cargo.toml
@@ -18,9 +18,12 @@ default = ["std"]
 std = ["alloc"]
 alloc = []
 
+[dependencies]
+internals = { package = "bitcoin-internals", version = "0.3.0" }
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 
 [lints.rust]
-unexpected_cfgs = { level = "deny", check-cfg = ['cfg(rust_v_1_72)', 'cfg(rust_v_1_73)', 'cfg(rust_v_1_75)', 'cfg(rust_v_1_78)'] }
+unexpected_cfgs = { level = "deny" }
diff --git a/io/build.rs b/io/build.rs
deleted file mode 100644
index 2b741ca0d..000000000
--- a/io/build.rs
+++ /dev/null
@@ -1,37 +0,0 @@
-fn main() {
-    let rustc = std::env::var_os("RUSTC");
-    let rustc = rustc.as_ref().map(std::path::Path::new).unwrap_or_else(|| "rustc".as_ref());
-    let output = std::process::Command::new(rustc)
-        .arg("--version")
-        .output()
-        .unwrap_or_else(|error| panic!("failed to run `{:?} --version`: {:?}", rustc, error));
-    assert!(output.status.success(), "{:?} -- version returned non-zero exit code", rustc);
-    let stdout = String::from_utf8(output.stdout).expect("rustc produced non-UTF-8 output");
-    let version_prefix = "rustc ";
-    if !stdout.starts_with(version_prefix) {
-        panic!("unexpected rustc output: {}", stdout);
-    }
-
-    let version = &stdout[version_prefix.len()..];
-    let end = version.find(&[' ', '-'] as &[_]).unwrap_or(version.len());
-    let version = &version[..end];
-    let mut version_components = version.split('.');
-    let major = version_components.next().unwrap();
-    assert_eq!(major, "1", "unexpected Rust major version");
-    let minor = version_components
-        .next()
-        .unwrap_or("0")
-        .parse::<u64>()
-        .expect("invalid Rust minor version");
-
-    let msrv = std::env::var("CARGO_PKG_RUST_VERSION").unwrap();
-    let mut msrv = msrv.split(".");
-    let msrv_major = msrv.next().unwrap();
-    assert_eq!(msrv_major, "1", "unexpected Rust major version");
-    let msrv_minor = msrv.next().unwrap().parse::<u64>().unwrap();
-
-    // print cfg for all interesting versions less than or equal to minor
-    for version in msrv_minor..=minor {
-        println!("cargo:rustc-cfg=rust_v_1_{}", version);
-    }
-}
diff --git a/io/src/bridge.rs b/io/src/bridge.rs
index 85e999167..91bad35e2 100644
--- a/io/src/bridge.rs
+++ b/io/src/bridge.rs
@@ -1,5 +1,6 @@
 #[cfg(feature = "alloc")]
 use alloc::boxed::Box;
+use internals::rust_version;
 
 /// A bridging wrapper providing the IO traits for types that already implement `std` IO traits.
 #[repr(transparent)]
@@ -304,24 +305,40 @@ macro_rules! impl_our {
     };
 }
 
-#[cfg(rust_v_1_72)]
-impl_our! {
-    impl<R: std::io::Read> Read for std::io::BufReader<R> where R: ?Sized
-}
+rust_version! {
+    if >= 1.72 {
+        impl_our! {
+            impl<R: std::io::Read> Read for std::io::BufReader<R> where R: ?Sized
+        }
 
-#[cfg(not(rust_v_1_72))]
-impl_our! {
-    impl<R: std::io::Read> Read for std::io::BufReader<R>
-}
+        impl_our! {
+            impl<R: std::io::Read> BufRead for std::io::BufReader<R> where R: ?Sized
+        }
 
-#[cfg(rust_v_1_72)]
-impl_our! {
-    impl<R: std::io::Read> BufRead for std::io::BufReader<R> where R: ?Sized
-}
+        impl_our! {
+            impl<W: std::io::Write> Write for std::io::BufWriter<W> where W: ?Sized
+        }
 
-#[cfg(not(rust_v_1_72))]
-impl_our! {
-    impl<R: std::io::Read> BufRead for std::io::BufReader<R>
+        impl_our! {
+            impl<W: std::io::Write> Write for std::io::LineWriter<W> where W: ?Sized
+        }
+    } else {
+        impl_our! {
+            impl<R: std::io::Read> Read for std::io::BufReader<R>
+        }
+
+        impl_our! {
+            impl<R: std::io::Read> BufRead for std::io::BufReader<R>
+        }
+
+        impl_our! {
+            impl<W: std::io::Write> Write for std::io::BufWriter<W>
+        }
+
+        impl_our! {
+            impl<W: std::io::Write> Write for std::io::LineWriter<W>
+        }
+    }
 }
 
 impl std::io::Write for super::Sink {
@@ -335,26 +352,6 @@ impl std::io::Write for super::Sink {
     fn flush(&mut self) -> std::io::Result<()> { Ok(()) }
 }
 
-#[cfg(rust_v_1_72)]
-impl_our! {
-    impl<W: std::io::Write> Write for std::io::BufWriter<W> where W: ?Sized
-}
-
-#[cfg(not(rust_v_1_72))]
-impl_our! {
-    impl<W: std::io::Write> Write for std::io::BufWriter<W>
-}
-
-#[cfg(rust_v_1_72)]
-impl_our! {
-    impl<W: std::io::Write> Write for std::io::LineWriter<W> where W: ?Sized
-}
-
-#[cfg(not(rust_v_1_72))]
-impl_our! {
-    impl<W: std::io::Write> Write for std::io::LineWriter<W>
-}
-
 impl_our! {
     impl<R: std::io::Read> Read for std::io::Take<R>
 }
@@ -399,15 +396,25 @@ impl_our! {
     impl BufRead for std::io::Empty
 }
 
-#[cfg(rust_v_1_73)]
-impl_our! {
-    impl Write for std::io::Empty
-}
+rust_version! {
+    if >= 1.73 {
+        impl_our! {
+            impl Write for std::io::Empty
+        }
 
-// No idea why &Empty impls Write but not Read + BufRead
-#[cfg(rust_v_1_73)]
-impl_our! {
-    impl Write for &'_ std::io::Empty
+        // No idea why &Empty impls Write but not Read + BufRead
+        impl_our! {
+            impl Write for &'_ std::io::Empty
+        }
+
+        impl_our! {
+            impl Read for std::sync::Arc<std::fs::File>
+        }
+
+        impl_our! {
+            impl Write for std::sync::Arc<std::fs::File>
+        }
+    }
 }
 
 impl_our! {
@@ -418,9 +425,12 @@ impl_our! {
     impl Read for std::io::Stdin
 }
 
-#[cfg(rust_v_1_78)]
-impl_our! {
-    impl Read for &'_ std::io::Stdin
+rust_version! {
+    if >= 1.78 {
+        impl_our! {
+            impl Read for &'_ std::io::Stdin
+        }
+    }
 }
 
 impl_our! {
@@ -463,16 +473,6 @@ impl_our! {
     impl Write for &'_ std::fs::File
 }
 
-#[cfg(rust_v_1_73)]
-impl_our! {
-    impl Read for std::sync::Arc<std::fs::File>
-}
-
-#[cfg(rust_v_1_73)]
-impl_our! {
-    impl Write for std::sync::Arc<std::fs::File>
-}
-
 impl_our! {
     impl Read for std::net::TcpStream
 }
@@ -526,14 +526,16 @@ impl_our! {
     impl Write for &'_ std::process::ChildStdin
 }
 
-#[cfg(rust_v_1_75)]
-impl_our! {
-    impl Read for std::collections::VecDeque<u8>
-}
+rust_version! {
+    if >= 1.75 {
+        impl_our! {
+            impl Read for std::collections::VecDeque<u8>
+        }
 
-#[cfg(rust_v_1_75)]
-impl_our! {
-    impl BufRead for std::collections::VecDeque<u8>
+        impl_our! {
+            impl BufRead for std::collections::VecDeque<u8>
+        }
+    }
 }
 
 impl_our! {