diff --git a/compiler/rustc_target/src/asm/arm.rs b/compiler/rustc_target/src/asm/arm.rs
index 4c323fc35d643..b7aca6cbbe956 100644
--- a/compiler/rustc_target/src/asm/arm.rs
+++ b/compiler/rustc_target/src/asm/arm.rs
@@ -1,5 +1,5 @@
 use super::{InlineAsmArch, InlineAsmType};
-use crate::spec::Target;
+use crate::spec::{RelocModel, Target};
 use rustc_macros::HashStable_Generic;
 use std::fmt;
 
@@ -88,6 +88,18 @@ fn frame_pointer_r7(
     }
 }
 
+fn rwpi_enabled(
+    _arch: InlineAsmArch,
+    _has_feature: impl FnMut(&str) -> bool,
+    target: &Target,
+) -> Result<(), &'static str> {
+    if let RelocModel::Rwpi | RelocModel::RopiRwpi = target.relocation_model {
+        Err("the RWPI static base register (r9) cannot be used as an operand for inline asm")
+    } else {
+        Ok(())
+    }
+}
+
 def_regs! {
     Arm ArmInlineAsmReg ArmInlineAsmRegClass {
         r0: reg, reg_thumb = ["r0", "a1"],
@@ -98,6 +110,7 @@ def_regs! {
         r5: reg, reg_thumb = ["r5", "v2"],
         r7: reg, reg_thumb = ["r7", "v4"] % frame_pointer_r7,
         r8: reg = ["r8", "v5"],
+        r9: reg = ["r9", "v6", "rfp"] % rwpi_enabled,
         r10: reg = ["r10", "sl"],
         r11: reg = ["r11", "fp"] % frame_pointer_r11,
         r12: reg = ["r12", "ip"],
@@ -183,9 +196,7 @@ def_regs! {
         q14: qreg = ["q14"],
         q15: qreg = ["q15"],
         #error = ["r6", "v3"] =>
-            "r6 is used internally by LLVM and cannot be used as an operand for inline asm",
-        #error = ["r9", "v6", "rfp"] =>
-            "r9 is used internally by LLVM and cannot be used as an operand for inline asm",
+            "the base pointer (r6) cannot be used as an operand for inline asm",
         #error = ["r13", "sp"] =>
             "the stack pointer cannot be used as an operand for inline asm",
         #error = ["r15", "pc"] =>