diff --git a/abi_version.c b/abi_version.c
index 5c3931f..5321d57 100644
--- a/abi_version.c
+++ b/abi_version.c
@@ -61,7 +61,7 @@ static int known_abi_count =
 	}\
 } while(0)
 
-static enum objc_gc_mode current_gc_mode = GC_Optional;
+PRIVATE enum objc_gc_mode current_gc_mode = GC_Optional;
 
 static BOOL endsWith(const char *string, const char *suffix)
 {
diff --git a/gc_boehm.c b/gc_boehm.c
index a74629d..c6d8b19 100644
--- a/gc_boehm.c
+++ b/gc_boehm.c
@@ -531,6 +531,9 @@ static void init(void)
 
 BOOL objc_collecting_enabled(void)
 {
+	// Lock the GC in the current state once it's been queried.  This prevents
+	// the loading of any modules with an incompatible GC mode.
+	current_gc_mode = isGCEnabled ? GC_Required : GC_None;
 	return isGCEnabled;
 }
 
diff --git a/gc_ops.h b/gc_ops.h
index 54045c0..2f84153 100644
--- a/gc_ops.h
+++ b/gc_ops.h
@@ -54,6 +54,10 @@ enum objc_gc_mode
 /**
  * The current Objective-C garbage collection mode.
  */
+extern enum objc_gc_mode current_gc_mode;
+/**
+ * Have we loaded any code that triggers the ObjC GC support?
+ */
 extern BOOL isGCEnabled;
 
 /**