diff --git a/charon/src/bin/charon-driver/main.rs b/charon/src/bin/charon-driver/main.rs
index 8f563806f..d6f8dc697 100644
--- a/charon/src/bin/charon-driver/main.rs
+++ b/charon/src/bin/charon-driver/main.rs
@@ -241,7 +241,6 @@ fn main() {
     trace!("Compiler arguments: {:?}", compiler_args);
 
     // Call the Rust compiler with our custom callback.
-    let errors_as_warnings = options.errors_as_warnings;
     let mut callback = CharonCallbacks::new(options);
     let mut res = callback.run_compiler(compiler_args);
     let CharonCallbacks {
@@ -253,7 +252,7 @@ fn main() {
 
     if !options.no_serialize {
         // # Final step: generate the files.
-        if res.is_ok() || options.errors_as_warnings {
+        if res.is_ok() || !options.error_on_warnings {
             // `crate_data` is set by our callbacks when there is no fatal error.
             if let Some(crate_data) = crate_data {
                 let dest_file = match options.dest_file.clone() {
@@ -276,7 +275,7 @@ fn main() {
         }
     }
 
-    if !errors_as_warnings && matches!(res, Err(CharonFailure::Panic)) {
+    if options.error_on_warnings && matches!(res, Err(CharonFailure::Panic)) {
         // If we emitted any error, the call into rustc will panic. Hence we assume this is
         // just a normal failure.
         // TODO: emit errors ourselves to avoid this (#409).
@@ -286,7 +285,7 @@ fn main() {
     match res {
         Ok(()) => {
             if error_count > 0 {
-                assert!(errors_as_warnings);
+                assert!(!options.error_on_warnings);
                 let msg = format!("The extraction generated {} warnings", error_count);
                 log::warn!("{}", msg);
             }
@@ -296,7 +295,7 @@ fn main() {
             if matches!(err, CharonFailure::Panic) {
                 // This is a real panic, exit with the standard rust panic error code.
                 std::process::exit(101);
-            } else if !errors_as_warnings {
+            } else if options.error_on_warnings {
                 std::process::exit(1);
             }
         }
diff --git a/charon/src/bin/charon-driver/translate/translate_crate_to_ullbc.rs b/charon/src/bin/charon-driver/translate/translate_crate_to_ullbc.rs
index e7da2e806..7a0027864 100644
--- a/charon/src/bin/charon-driver/translate/translate_crate_to_ullbc.rs
+++ b/charon/src/bin/charon-driver/translate/translate_crate_to_ullbc.rs
@@ -368,7 +368,6 @@ pub fn translate<'tcx, 'ctx>(options: &CliOpts, tcx: TyCtxt<'tcx>) -> TransformC
         tcx,
         hax::options::Options {
             inline_macro_calls: Vec::new(),
-            // downgrade_errors: options.errors_as_warnings,
         },
     );
 
@@ -386,7 +385,7 @@ pub fn translate<'tcx, 'ctx>(options: &CliOpts, tcx: TyCtxt<'tcx>) -> TransformC
 
     let mut error_ctx = ErrorCtx {
         continue_on_failure: !options.abort_on_error,
-        errors_as_warnings: options.errors_as_warnings,
+        error_on_warnings: options.error_on_warnings,
         dcx: tcx.dcx(),
         external_decls_with_errors: HashSet::new(),
         ignored_failed_decls: HashSet::new(),
diff --git a/charon/src/bin/generate-ml/main.rs b/charon/src/bin/generate-ml/main.rs
index 31a3e44bc..191018b87 100644
--- a/charon/src/bin/generate-ml/main.rs
+++ b/charon/src/bin/generate-ml/main.rs
@@ -949,7 +949,6 @@ fn main() -> Result<()> {
         // Call charon on itself
         let mut cmd = Command::cargo_bin("charon")?;
         cmd.arg("--cargo-arg=--lib");
-        cmd.arg("--errors-as-warnings");
         cmd.arg("--hide-marker-traits");
         cmd.arg("--dest-file");
         cmd.arg(&charon_llbc);
diff --git a/charon/src/errors.rs b/charon/src/errors.rs
index 826577aa4..b6a7dc9b0 100644
--- a/charon/src/errors.rs
+++ b/charon/src/errors.rs
@@ -68,8 +68,8 @@ pub struct DepSource {
 pub struct ErrorCtx<'ctx> {
     /// If true, do not abort on the first error and attempt to extract as much as possible.
     pub continue_on_failure: bool,
-    /// If true, print the errors as warnings, and do not abort.
-    pub errors_as_warnings: bool,
+    /// If true, print the warnings as errors, and abort if any errors were raised.
+    pub error_on_warnings: bool,
 
     /// The compiler session, used for displaying errors.
     #[cfg(feature = "rustc")]
@@ -106,19 +106,19 @@ impl ErrorCtx<'_> {
         msg: &str,
     ) {
         let msg = msg.to_string();
-        if self.errors_as_warnings {
-            self.dcx.span_warn(span, msg);
-        } else {
+        if self.error_on_warnings {
             self.dcx.span_err(span, msg);
+        } else {
+            self.dcx.span_warn(span, msg);
         }
     }
     #[cfg(not(feature = "rustc"))]
     pub(crate) fn span_err_no_register(&self, _span: Span, msg: &str) {
         let msg = msg.to_string();
         if self.errors_as_warnings {
-            error!("{}", msg);
-        } else {
             warn!("{}", msg);
+        } else {
+            error!("{}", msg);
         }
     }
 
diff --git a/charon/src/options.rs b/charon/src/options.rs
index 596115d06..24b53f88a 100644
--- a/charon/src/options.rs
+++ b/charon/src/options.rs
@@ -177,9 +177,9 @@ pub struct CliOpts {
     #[serde(default)]
     pub abort_on_error: bool,
     /// Print the errors as warnings
-    #[clap(long = "errors-as-warnings", help = "Report the errors as warnings")]
+    #[clap(long = "error-on-warnings", help = "Consider any warnings as errors")]
     #[serde(default)]
-    pub errors_as_warnings: bool,
+    pub error_on_warnings: bool,
     #[clap(
         long = "no-serialize",
         help = "Don't serialize the final (U)LLBC to a file."
@@ -231,10 +231,5 @@ impl CliOpts {
             !self.mir_promoted || !self.mir_optimized,
             "Can't use --mir_promoted and --mir_optimized at the same time"
         );
-
-        assert!(
-            !self.abort_on_error || !self.errors_as_warnings,
-            "Can't use --abort-on-error and --errors-as-warnings at the same time"
-        );
     }
 }
diff --git a/charon/tests/cargo.rs b/charon/tests/cargo.rs
index de1867d34..9693c91e5 100644
--- a/charon/tests/cargo.rs
+++ b/charon/tests/cargo.rs
@@ -29,6 +29,7 @@ fn perform_test(test_case: &Case, action: Action) -> anyhow::Result<()> {
     // Call charon
     let mut cmd = Command::cargo_bin("charon")?;
     cmd.current_dir(&test_case.dir);
+    cmd.arg("--error-on-warnings");
     cmd.arg("--print-llbc");
     cmd.arg("--dest-file");
     cmd.arg(test_case.expected.with_extension("llbc"));
diff --git a/charon/tests/popular-crates.rs b/charon/tests/popular-crates.rs
index b28f13b2e..3d1732a74 100644
--- a/charon/tests/popular-crates.rs
+++ b/charon/tests/popular-crates.rs
@@ -102,7 +102,6 @@ fn process_crate(version: &Version) -> Result<()> {
         .stderr(Stdio::piped())
         .current_dir(&crate_dir)
         .arg("--hide-marker-traits")
-        .arg("--errors-as-warnings")
         .arg("--dest-file")
         .arg(&llbc_path)
         .spawn()?;
diff --git a/charon/tests/ui.rs b/charon/tests/ui.rs
index cc780eb22..4da5c1e4e 100644
--- a/charon/tests/ui.rs
+++ b/charon/tests/ui.rs
@@ -177,6 +177,7 @@ fn perform_test(test_case: &Case, action: Action) -> anyhow::Result<()> {
     let mut cmd = Command::cargo_bin("charon")?;
     cmd.arg("--no-cargo");
 
+    cmd.arg("--error-on-warnings");
     cmd.arg("--print-llbc");
     cmd.arg("--crate=test_crate");
     cmd.arg("--input");
diff --git a/charon/tests/ui/trait-instance-id.rs b/charon/tests/ui/trait-instance-id.rs
index 25693b71e..e8b1c92d9 100644
--- a/charon/tests/ui/trait-instance-id.rs
+++ b/charon/tests/ui/trait-instance-id.rs
@@ -1,4 +1,3 @@
-//@ charon-args=--errors-as-warnings
 // This (for now) produces `TraitRefKind::Unknown`; it's a regression test because we used to
 // not parse this in `charon-ml`.
 fn main() {