diff --git a/src/core/exceptions.c b/src/core/exceptions.c
index f5429fbc10..b4533904c2 100644
--- a/src/core/exceptions.c
+++ b/src/core/exceptions.c
@@ -648,10 +648,10 @@ static void panic_unhandled_cat(MVMThreadContext *tc, MVMuint32 cat) {
     }
     else {
         if (tc->nested_interpreter)
-            fprintf(stderr, "An unhandled exception occurred in a native callback.\n"
-                    "This situation is not recoverable, and the program will terminate.\n"
-                    "The stack trace below helps indicate which library needs fixing.\n"
-                    "The exception was thrown at:\n");
+            fputs("An unhandled exception occurred in a native callback.\n"
+                  "This situation is not recoverable, and the program will terminate.\n"
+                  "The stack trace below helps indicate which library needs fixing.\n"
+                  "The exception was thrown at:\n", stderr);
         else
             fprintf(stderr, "No exception handler located for %s\n", cat_name(tc, cat));
         MVM_dump_backtrace(tc);
@@ -843,11 +843,11 @@ void MVM_exception_resume(MVMThreadContext *tc, MVMObject *ex_obj) {
  */
 MVM_NO_RETURN void MVM_panic(MVMint32 exitCode, const char *messageFormat, ...) {
     va_list args;
-    fprintf(stderr, "MoarVM panic: ");
+    fputs("MoarVM panic: ", stderr);
     va_start(args, messageFormat);
     vfprintf(stderr, messageFormat, args);
     va_end(args);
-    fwrite("\n", 1, 1, stderr);
+    fputc('\n', stderr);
     if (crash_on_error)
         abort();
     else
@@ -862,13 +862,23 @@ MVM_NO_RETURN void MVM_panic_allocation_failed(size_t len) {
  * process to indicate that we've made an error */
 MVM_NO_RETURN void MVM_oops(MVMThreadContext *tc, const char *messageFormat, ...) {
     va_list args;
-    fprintf(stderr, "MoarVM oops: ");
+    fprintf(stderr, "MoarVM oops%s: ",
+            !tc ? " with NULL tc" :
+            (MVMObject *) tc->thread_obj == tc->instance->spesh_thread
+            ? " in spesh thread" :
+            (MVMObject *) tc->thread_obj == tc->instance->event_loop_thread
+            ? " in event loop thread" : "");
     va_start(args, messageFormat);
     vfprintf(stderr, messageFormat, args);
     va_end(args);
-    fprintf(stderr, "\n");
+    fputc('\n', stderr);
+
+    /* Our caller is seriously buggy if tc is NULL */
+    if (!tc)
+        abort();
+
     MVM_dump_backtrace(tc);
-    fprintf(stderr, "\n");
+    fputc('\n', stderr);
     exit(1);
 }
 
@@ -899,6 +909,23 @@ MVM_NO_RETURN void MVM_exception_throw_adhoc_free(MVMThreadContext *tc, char **w
 MVM_NO_RETURN void MVM_exception_throw_adhoc_free_va(MVMThreadContext *tc, char **waste, const char *messageFormat, va_list args) {
     LocatedHandler lh;
     MVMException *ex;
+    const char *special = !tc ? " with NULL tc"
+        : (MVMObject *) tc->thread_obj == tc->instance->spesh_thread ? " in spesh thread"
+        : (MVMObject *) tc->thread_obj == tc->instance->event_loop_thread ? " in event loop thread" : NULL;
+
+    if (special) {
+        fprintf(stderr, "MoarVM exception%s treated as oops: ", special);
+        vfprintf(stderr, messageFormat, args);
+        va_end(args);
+        fputc('\n', stderr);
+        if (!tc)
+            abort();
+
+        MVM_dump_backtrace(tc);
+        fputc('\n', stderr);
+        exit(1);
+    }
+
     /* The current frame will be assigned as the thrower of the exception, so
      * force it onto the heap before we begin. */
     if (tc->cur_frame)
@@ -942,7 +969,7 @@ MVM_NO_RETURN void MVM_exception_throw_adhoc_free_va(MVMThreadContext *tc, char
         if (crash_on_error) {
             /* Yes, abort. */
             vfprintf(stderr, messageFormat, args);
-            fwrite("\n", 1, 1, stderr);
+            fputc('\n', stderr);
             MVM_dump_backtrace(tc);
             abort();
         }