diff --git a/README.md b/README.md
index fdc746ead5..ee77ea4d64 100644
--- a/README.md
+++ b/README.md
@@ -461,9 +461,6 @@ to Miri failing to detect cases of undefined behavior in a program.
   disables the randomization of the next thread to be picked, instead fixing a round-robin schedule.
   Note however that other aspects of Miri's concurrency behavior are still randomize; use
   `-Zmiri-deterministic-concurrency` to disable them all.
-* `-Zmiri-force-intrinsic-fallback` forces the use of the "fallback" body for all intrinsics that
-  have one. This is useful to test the fallback bodies, but should not be used otherwise. It is
-  **unsound** since the fallback body might not be checking for all UB.
 * `-Zmiri-native-lib=<path to a shared object file or folder>` is an experimental flag for providing
   support for calling native functions from inside the interpreter via FFI. The flag is supported
   only on Unix systems. Functions not provided by that file are still executed via the usual Miri
diff --git a/src/bin/miri.rs b/src/bin/miri.rs
index 442f96ffaa..372829ea07 100644
--- a/src/bin/miri.rs
+++ b/src/bin/miri.rs
@@ -536,8 +536,6 @@ fn main() -> ExitCode {
         } else if arg == "-Zmiri-ignore-leaks" {
             miri_config.ignore_leaks = true;
             miri_config.collect_leak_backtraces = false;
-        } else if arg == "-Zmiri-force-intrinsic-fallback" {
-            miri_config.force_intrinsic_fallback = true;
         } else if arg == "-Zmiri-deterministic-floats" {
             miri_config.float_nondet = false;
         } else if arg == "-Zmiri-no-extra-rounding-error" {
diff --git a/src/eval.rs b/src/eval.rs
index 19b6ff75f9..f33dc9d070 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -162,8 +162,6 @@ pub struct MiriConfig {
     pub address_reuse_cross_thread_rate: f64,
     /// Round Robin scheduling with no preemption.
     pub fixed_scheduling: bool,
-    /// Always prefer the intrinsic fallback body over the native Miri implementation.
-    pub force_intrinsic_fallback: bool,
     /// Whether floating-point operations can behave non-deterministically.
     pub float_nondet: bool,
     /// Whether floating-point operations can have a non-deterministic rounding error.
@@ -210,7 +208,6 @@ impl Default for MiriConfig {
             address_reuse_rate: 0.5,
             address_reuse_cross_thread_rate: 0.1,
             fixed_scheduling: false,
-            force_intrinsic_fallback: false,
             float_nondet: true,
             float_rounding_error: FloatRoundingErrorMode::Random,
             short_fd_operations: true,
diff --git a/src/intrinsics/mod.rs b/src/intrinsics/mod.rs
index a8eed1b8e0..4cfb0930fd 100644
--- a/src/intrinsics/mod.rs
+++ b/src/intrinsics/mod.rs
@@ -46,16 +46,6 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
     ) -> InterpResult<'tcx, Option<ty::Instance<'tcx>>> {
         let this = self.eval_context_mut();
 
-        // Force use of fallback body, if available.
-        if this.machine.force_intrinsic_fallback
-            && !this.tcx.intrinsic(instance.def_id()).unwrap().must_be_overridden
-        {
-            return interp_ok(Some(ty::Instance {
-                def: ty::InstanceKind::Item(instance.def_id()),
-                args: instance.args,
-            }));
-        }
-
         // See if the core engine can handle this intrinsic.
         if this.eval_intrinsic(instance, args, dest, ret)? {
             return interp_ok(None);
diff --git a/src/machine.rs b/src/machine.rs
index 34dce8a7f2..cc6a15d3f7 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -657,9 +657,6 @@ pub struct MiriMachine<'tcx> {
     /// Cache for `mangle_internal_symbol`.
     pub(crate) mangle_internal_symbol_cache: FxHashMap<&'static str, String>,
 
-    /// Always prefer the intrinsic fallback body over the native Miri implementation.
-    pub force_intrinsic_fallback: bool,
-
     /// Whether floating-point operations can behave non-deterministically.
     pub float_nondet: bool,
     /// Whether floating-point operations can have a non-deterministic rounding error.
@@ -838,7 +835,6 @@ impl<'tcx> MiriMachine<'tcx> {
             pthread_condvar_sanity: Cell::new(false),
             allocator_shim_symbols: Self::allocator_shim_symbols(tcx),
             mangle_internal_symbol_cache: Default::default(),
-            force_intrinsic_fallback: config.force_intrinsic_fallback,
             float_nondet: config.float_nondet,
             float_rounding_error: config.float_rounding_error,
             short_fd_operations: config.short_fd_operations,
@@ -1074,7 +1070,6 @@ impl VisitProvenance for MiriMachine<'_> {
             pthread_condvar_sanity: _,
             allocator_shim_symbols: _,
             mangle_internal_symbol_cache: _,
-            force_intrinsic_fallback: _,
             float_nondet: _,
             float_rounding_error: _,
             short_fd_operations: _,
diff --git a/tests/pass/c-variadic.rs b/tests/pass/c-variadic.rs
index e17d6820c5..df3df00851 100644
--- a/tests/pass/c-variadic.rs
+++ b/tests/pass/c-variadic.rs
@@ -121,13 +121,6 @@ fn equal_up_to_free_lifetime() {
 }
 
 fn clone() {
-    if cfg!(force_intrinsic_fallback) {
-        // Skip this test when we use the fallback bodies. The fallback body does
-        // not hook into the Miri allocation bookkeeping for variable argument lists
-        // and would would falsely report UB.
-        return;
-    }
-
     unsafe extern "C" fn clone_the_va_list(args: ...) {
         // The implicit `drop` will catch a `VaList` that isn't properly initialized.
         let _ = args.clone();
@@ -137,13 +130,6 @@ fn clone() {
 }
 
 fn clone_and_advance() {
-    if cfg!(force_intrinsic_fallback) {
-        // Skip this test when we use the fallback bodies. The fallback body does
-        // not hook into the Miri allocation bookkeeping for variable argument lists
-        // and would would falsely report UB.
-        return;
-    }
-
     unsafe extern "C" fn variadic(mut a: ...) {
         unsafe {
             let mut b = a.clone();
diff --git a/tests/pass/float.rs b/tests/pass/float.rs
index e57bbeb938..703077e303 100644
--- a/tests/pass/float.rs
+++ b/tests/pass/float.rs
@@ -1529,12 +1529,6 @@ fn test_fmuladd() {
 }
 
 fn test_non_determinism() {
-    if cfg!(force_intrinsic_fallback) {
-        // Skip this test when we use the fallback bodies, as that one is deterministic.
-        // (CI sets `--cfg force_intrinsic_fallback` together with `-Zmiri-force-intrinsic-fallback`.)
-        return;
-    }
-
     use std::intrinsics::{
         fadd_algebraic, fadd_fast, fdiv_algebraic, fdiv_fast, fmul_algebraic, fmul_fast,
         frem_algebraic, frem_fast, fsub_algebraic, fsub_fast,
diff --git a/tests/pass/float_nan.rs b/tests/pass/float_nan.rs
index 4ec5a7e9c2..cf4cbe4529 100644
--- a/tests/pass/float_nan.rs
+++ b/tests/pass/float_nan.rs
@@ -541,12 +541,6 @@ fn test_simd() {
 }
 
 fn main() {
-    if cfg!(force_intrinsic_fallback) {
-        // Skip this test when we use the fallback bodies, as that one is deterministic.
-        // (CI sets `--cfg force_intrinsic_fallback` together with `-Zmiri-force-intrinsic-fallback`.)
-        return;
-    }
-
     // Check our constants against std, just to be sure.
     // We add 1 since our numbers are the number of bits stored
     // to represent the value, and std has the precision of the value,
diff --git a/tests/pass/intrinsics/intrinsics.rs b/tests/pass/intrinsics/intrinsics.rs
index c6ccadf031..8e3a9218df 100644
--- a/tests/pass/intrinsics/intrinsics.rs
+++ b/tests/pass/intrinsics/intrinsics.rs
@@ -37,11 +37,7 @@ fn main() {
     assert_eq!(intrinsics::likely(false), false);
     assert_eq!(intrinsics::unlikely(true), true);
 
-    // Skip this test when we use the fallback bodies, as that one is deterministic.
-    // (CI sets `--cfg force_intrinsic_fallback` together with `-Zmiri-force-intrinsic-fallback`.)
-    if !cfg!(force_intrinsic_fallback) {
-        check_nondet(|| intrinsics::is_val_statically_known(0));
-    }
+    check_nondet(|| intrinsics::is_val_statically_known(0));
 
     intrinsics::forget(Bomb);