diff --git a/doc/jit/zjit.md b/doc/jit/zjit.md
index 2b8bd640f1fca0..ebe5cc4f9bb7b3 100644
--- a/doc/jit/zjit.md
+++ b/doc/jit/zjit.md
@@ -365,7 +365,6 @@ Note that this disables profiling. To inject interpreter profiles into ZJIT, con
 ```bash
 ./miniruby --zjit --zjit-dump-hir -e "30.times { 1 + 1 }"
 ```
-```
 
 ### Viewing HIR in Iongraph
 
diff --git a/gc.c b/gc.c
index 1d3f6fa6ed15be..e0757a20dd48f4 100644
--- a/gc.c
+++ b/gc.c
@@ -198,36 +198,6 @@ rb_gc_initialize_vm_context(struct rb_gc_vm_context *context)
     context->ec = GET_EC();
 }
 
-#if USE_MODULAR_GC
-void
-rb_gc_worker_thread_set_vm_context(struct rb_gc_vm_context *context)
-{
-    rb_native_mutex_lock(&context->lock);
-
-    GC_ASSERT(rb_current_execution_context(false) == NULL);
-
-#ifdef RB_THREAD_LOCAL_SPECIFIER
-    rb_current_ec_set(context->ec);
-#else
-    native_tls_set(ruby_current_ec_key, context->ec);
-#endif
-}
-
-void
-rb_gc_worker_thread_unset_vm_context(struct rb_gc_vm_context *context)
-{
-    rb_native_mutex_unlock(&context->lock);
-
-    GC_ASSERT(rb_current_execution_context(true) == context->ec);
-
-#ifdef RB_THREAD_LOCAL_SPECIFIER
-    rb_current_ec_set(NULL);
-#else
-    native_tls_set(ruby_current_ec_key, NULL);
-#endif
-}
-#endif
-
 bool
 rb_gc_event_hook_required_p(rb_event_flag_t event)
 {
diff --git a/gc/gc.h b/gc/gc.h
index 31ce736778d295..2809c7a128b824 100644
--- a/gc/gc.h
+++ b/gc/gc.h
@@ -101,8 +101,6 @@ MODULAR_GC_FN bool rb_gc_obj_needs_cleanup_p(VALUE obj);
 MODULAR_GC_FN bool rb_gc_event_hook_required_p(rb_event_flag_t event);
 MODULAR_GC_FN void *rb_gc_get_ractor_newobj_cache(void);
 MODULAR_GC_FN void rb_gc_initialize_vm_context(struct rb_gc_vm_context *context);
-MODULAR_GC_FN void rb_gc_worker_thread_set_vm_context(struct rb_gc_vm_context *context);
-MODULAR_GC_FN void rb_gc_worker_thread_unset_vm_context(struct rb_gc_vm_context *context);
 MODULAR_GC_FN void rb_gc_move_obj_during_marking(VALUE from, VALUE to);
 MODULAR_GC_FN void rb_gc_print_backtrace();
 #endif
diff --git a/include/ruby/internal/attr/format.h b/include/ruby/internal/attr/format.h
index b3488ee00a36aa..7feff1c84637ff 100644
--- a/include/ruby/internal/attr/format.h
+++ b/include/ruby/internal/attr/format.h
@@ -22,6 +22,10 @@
  */
 #include "ruby/internal/has/attribute.h"
 
+#if defined(__MINGW32__)
+#include <stdio.h>              /* for __MINGW_PRINTF_FORMAT */
+#endif
+
 /** Wraps (or simulates) `__attribute__((format))` */
 #if RBIMPL_HAS_ATTRIBUTE(format)
 # define RBIMPL_ATTR_FORMAT(x, y, z) __attribute__((__format__(x, y, z)))
diff --git a/scheduler.c b/scheduler.c
index c2f370a22aee4e..3205bb3bc9a7c3 100644
--- a/scheduler.c
+++ b/scheduler.c
@@ -1111,6 +1111,9 @@ VALUE rb_fiber_scheduler_blocking_operation_wait(VALUE scheduler, void* (*functi
     operation->data2 = NULL;
     operation->unblock_function = NULL;
 
+    // Ensure that the blocking operation remains visible until this point:
+    RB_GC_GUARD(blocking_operation);
+
     // If the blocking operation was never executed, return Qundef to signal the caller to use rb_nogvl instead
     if (current_status == RB_FIBER_SCHEDULER_BLOCKING_OPERATION_STATUS_QUEUED) {
         return Qundef;
diff --git a/shape.c b/shape.c
index 2b4256e5f3068c..24f1394f6cd32f 100644
--- a/shape.c
+++ b/shape.c
@@ -1529,7 +1529,7 @@ Init_default_shapes(void)
     }
 
     if (heaps_count > SHAPE_ID_HEAP_INDEX_MAX) {
-        rb_bug("Init_default_shapes initialized with %lu heaps, only up to %u are supported", heaps_count, SHAPE_ID_HEAP_INDEX_MAX);
+        rb_bug("Init_default_shapes initialized with %zu heaps, only up to %u are supported", heaps_count, SHAPE_ID_HEAP_INDEX_MAX);
     }
 
     size_t index;