diff --git a/src/builtins/read.rs b/src/builtins/read.rs
index 5a53f3dc3..b386cc8f4 100644
--- a/src/builtins/read.rs
+++ b/src/builtins/read.rs
@@ -14,6 +14,7 @@
 use crate::input_common::decode_input_byte;
 use crate::input_common::terminal_protocols_disable_ifn;
 use crate::input_common::DecodeState;
+use crate::input_common::InvalidPolicy;
 use crate::nix::isatty;
 use crate::reader::commandline_set_buffer;
 use crate::reader::ReaderConfig;
@@ -358,16 +359,19 @@ fn read_one_char_at_a_time(
             unconsumed.push(b);
             nbytes += 1;
             let mut consumed = 0;
-            match decode_input_byte(buff, &mut state, &unconsumed, &mut consumed) {
+            match decode_input_byte(
+                buff,
+                InvalidPolicy::Passthrough,
+                &mut state,
+                &unconsumed,
+                &mut consumed,
+            ) {
                 DecodeState::Incomplete => continue,
                 DecodeState::Complete => {
                     unconsumed.clear();
                     break Some(buff.as_char_slice().last().unwrap());
                 }
-                DecodeState::Error => {
-                    state = zero_mbstate();
-                    unconsumed.clear();
-                }
+                DecodeState::Error => unreachable!(),
             }
         };
 
diff --git a/src/input_common.rs b/src/input_common.rs
index 0a24110c3..b614250f4 100644
--- a/src/input_common.rs
+++ b/src/input_common.rs
@@ -873,6 +873,7 @@ fn try_readch(&mut self, blocking: bool) -> Option<CharEvent> {
                         }
                         match decode_input_byte(
                             &mut seq,
+                            InvalidPolicy::Error,
                             &mut state,
                             &buffer[..i + 1],
                             &mut consumed,
@@ -1693,8 +1694,15 @@ pub(crate) enum DecodeState {
     Error,
 }
 
+#[derive(Eq, PartialEq)]
+pub(crate) enum InvalidPolicy {
+    Error,
+    Passthrough,
+}
+
 pub(crate) fn decode_input_byte(
     out_seq: &mut WString,
+    invalid_policy: InvalidPolicy,
     state: &mut mbstate_t,
     buffer: &[u8],
     consumed: &mut usize,
@@ -1710,6 +1718,19 @@ pub(crate) fn decode_input_byte(
         out_seq.push(res);
         return Complete;
     }
+    let mut invalid = |out_seq: &mut WString, log_error: fn()| match invalid_policy {
+        InvalidPolicy::Error => {
+            (log_error)();
+            Error
+        }
+        InvalidPolicy::Passthrough => {
+            for &b in &buffer[*consumed..] {
+                out_seq.push(encode_byte_to_char(b));
+            }
+            *consumed = buffer.len();
+            Complete
+        }
+    };
     let mut codepoint = u32::from(res);
     match unsafe {
         mbrtowc(
@@ -1721,9 +1742,7 @@ pub(crate) fn decode_input_byte(
     } as isize
     {
         -1 => {
-            FLOG!(reader, "Illegal input");
-            *consumed += 1;
-            return Error;
+            return invalid(out_seq, || FLOG!(reader, "Illegal input encoding"));
         }
         -2 => {
             // Sequence not yet complete.
@@ -1739,11 +1758,7 @@ pub(crate) fn decode_input_byte(
             return Complete;
         }
     }
-    for &b in &buffer[*consumed..] {
-        out_seq.push(encode_byte_to_char(b));
-        *consumed += 1;
-    }
-    Complete
+    invalid(out_seq, || FLOG!(reader, "Illegal codepoint"))
 }
 
 pub(crate) fn unblock_input(mut wait_guard: MutexGuard<Option<BlockingWait>>) -> bool {
diff --git a/tests/checks/read.fish b/tests/checks/read.fish
index bc96e3074..c3e087d94 100644
--- a/tests/checks/read.fish
+++ b/tests/checks/read.fish
@@ -431,3 +431,7 @@ printf \xf9\x98\xb1\x83\x8b | read -z out_of_range_codepoint
 set -S out_of_range_codepoint
 # CHECK: $out_of_range_codepoint: set in global scope, unexported, with 1 elements
 # CHECK: $out_of_range_codepoint[1]: |\Xf9\X98\Xb1\X83\X8b|
+
+printf \xff | { read invalid_utf8; set -S invalid_utf8 }
+# CHECK: $invalid_utf8: set in global scope, unexported, with 1 elements
+# CHECK: $invalid_utf8[1]: |\Xff|