diff --git a/core/relinker/CMakeLists.txt b/core/relinker/CMakeLists.txt
index 84ded5ebcd..f41f133525 100644
--- a/core/relinker/CMakeLists.txt
+++ b/core/relinker/CMakeLists.txt
@@ -556,6 +556,9 @@ if(BUILD_TESTING)
         endforeach()
         add_test(NAME tls_diagnostics COMMAND ${Python3_EXECUTABLE}
             ${CMAKE_CURRENT_SOURCE_DIR}/relinker/tests/test_tls_diagnostics.py $<TARGET_FILE:relinker>)
+        add_test(NAME ignored_string_segments COMMAND ${Python3_EXECUTABLE}
+            ${CMAKE_CURRENT_SOURCE_DIR}/relinker/tests/test_ignored_string_segments.py $<TARGET_FILE:relinker>)
+        set_tests_properties(ignored_string_segments PROPERTIES TIMEOUT 30)
         add_test(NAME call_zero_padding COMMAND ${Python3_EXECUTABLE}
             ${CMAKE_CURRENT_SOURCE_DIR}/relinker/tests/test_call_zero_padding.py $<TARGET_FILE:relinker>)
         set_tests_properties(call_zero_padding PROPERTIES TIMEOUT 60)
diff --git a/core/relinker/codegen/src/x86/X64InstructionDecoder.cpp b/core/relinker/codegen/src/x86/X64InstructionDecoder.cpp
index 78936363b4..809af1503d 100644
--- a/core/relinker/codegen/src/x86/X64InstructionDecoder.cpp
+++ b/core/relinker/codegen/src/x86/X64InstructionDecoder.cpp
@@ -627,6 +627,9 @@ DecodedInstructionInfo X64InstructionDecoder::DecodeInstruction(
     if ((!twoByteOpcode && op == OneByteLea) || (twoByteOpcode && op == TwoByteNopModRm))
         info.HasMemoryOperand = false;
 
+    if (!twoByteOpcode && (op == 0x6c || op == 0x6d || op == 0xaa || op == 0xab || op == 0xae || op == 0xaf))
+        info.SegmentPrefix = 0;
+
     info.FlowKind = ControlFlowKind::Sequential;
     return info;
 }
diff --git a/core/relinker/codegen/tests/DecoderLengthTests.cpp b/core/relinker/codegen/tests/DecoderLengthTests.cpp
index 95c85168d7..a3f0ade694 100644
--- a/core/relinker/codegen/tests/DecoderLengthTests.cpp
+++ b/core/relinker/codegen/tests/DecoderLengthTests.cpp
@@ -113,6 +113,15 @@ int main() {
             const auto bytes = parse(testCase.Bytes);
             require(!decoder.DecodeInstruction(bytes.data(), bytes.size()).TruncatesBranchTarget, "Branch target of " + std::string(testCase.Bytes) + " was reported as truncated");
         }
+        for (const auto segment : {0x64, 0x65}) {
+            for (const auto opcode : {0x6c, 0x6d, 0xaa, 0xab, 0xae, 0xaf, 0x6e, 0x6f, 0xa4, 0xa5, 0xa6, 0xa7, 0xac, 0xad}) {
+                const std::vector<std::uint8_t> bytes{static_cast<std::uint8_t>(segment), static_cast<std::uint8_t>(opcode)};
+                const auto info = decoder.DecodeInstruction(bytes.data(), bytes.size());
+                const bool fixedEs = opcode == 0x6c || opcode == 0x6d || opcode == 0xaa || opcode == 0xab || opcode == 0xae || opcode == 0xaf;
+                require(info.HasMemoryOperand, "A string instruction lost its implicit memory operand");
+                require(info.SegmentPrefix == (fixedEs ? 0 : segment), "Wrong effective segment for a string instruction");
+            }
+        }
         const auto threeDNow = parse("0f0f0d11223344a6");
         const auto threeDNowInfo = decoder.DecodeInstruction(threeDNow.data(), threeDNow.size());
         require(threeDNowInfo.HasModRm && threeDNowInfo.ModRmByte == 0x0d, "3DNow! ModRM was not reported");
diff --git a/core/relinker/relinker/tests/test_ignored_string_segments.py b/core/relinker/relinker/tests/test_ignored_string_segments.py
new file mode 100644
index 0000000000..25fb10cbb3
--- /dev/null
+++ b/core/relinker/relinker/tests/test_ignored_string_segments.py
@@ -0,0 +1,38 @@
+from pathlib import Path
+import subprocess
+import sys
+import tempfile
+
+from test_macos_output import MachO
+from test_tls_function_coverage import make_image, pe_bytes_at
+
+
+def main():
+    relinker = Path(sys.argv[1]).resolve()
+    with tempfile.TemporaryDirectory(prefix="anyps5-string-segments-") as directory:
+        work = Path(directory)
+        for target in ("windows", "macos"):
+            for segment in (0x64, 0x65):
+                for opcode in (0x6c, 0x6d, 0xaa, 0xab, 0xae, 0xaf):
+                    for prefixes in (b"", b"\x66", b"\xf3\x67", b"\xf2\x48"):
+                        instruction = bytes([segment]) + prefixes + bytes([opcode])
+                        body = instruction + b"\xc3"
+                        name = target + "-" + instruction.hex()
+                        source, output = work / (name + ".elf"), work / name
+                        source.write_bytes(make_image("register", "unwind", body=body))
+                        result = subprocess.run([str(relinker), "--" + target, "--skip-sce-module", str(source), str(output)],
+                                                capture_output=True, text=True, timeout=20)
+                        assert result.returncode == 0, (name, result.stdout, result.stderr)
+                        data = output.read_bytes()
+                        if target == "windows":
+                            actual = pe_bytes_at(data, 0x11240, len(body))
+                        else:
+                            segment_info = next(s for s in MachO(data).segments if s["vmaddr"] <= 0x140011240 < s["vmaddr"] + s["filesize"])
+                            offset = segment_info["fileoff"] + 0x140011240 - segment_info["vmaddr"]
+                            actual = data[offset:offset + len(body)]
+                        assert actual == body, (name, actual.hex(), body.hex())
+    print("Ignored string segment prefixes preserved on Windows and macOS")
+
+
+if __name__ == "__main__":
+    main()