diff --git a/CHANGELOG.md b/CHANGELOG.md
index 644c4b04..bbb790c3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,10 @@
   #> [1] -1
   ```
 
+### Bug fixes
+
+* `r_print!()` and `r_eprint!()` now can print strings containing `%`.
+
 ## [v0.6.3] (2024-05-05)
 
 ### New features
diff --git a/src/io.rs b/src/io.rs
index 5eaee360..621419a6 100644
--- a/src/io.rs
+++ b/src/io.rs
@@ -7,7 +7,7 @@ pub(crate) const LINEBREAK: [c_char; 2] = [b'\n' as _, b'\0' as _];
 pub fn r_print(msg: &str, linebreak: bool) {
     if !msg.is_empty() {
         // ignore error
-        let _ = r_stdout().write_all(msg.as_bytes());
+        let _ = r_stdout().write_all(msg.replace('%', "%%").as_bytes());
     }
 
     unsafe {
@@ -20,7 +20,7 @@ pub fn r_print(msg: &str, linebreak: bool) {
 pub fn r_eprint(msg: &str, linebreak: bool) {
     if !msg.is_empty() {
         // ignore error
-        let _ = r_stderr().write_all(msg.as_bytes());
+        let _ = r_stderr().write_all(msg.replace('%', "%%").as_bytes());
     }
 
     unsafe {