Index: src/macros.h
==================================================================
--- src/macros.h
+++ src/macros.h
@@ -358,11 +358,17 @@
 			    OF_STRINGIFY(__LINE__),			\
 			    "Failed to ensure condition:\n" #cond);	\
 	} while(0)
 #else
 @class OFConstantString;
+# ifdef __cplusplus
+extern "C" {
+# endif
 extern void OFLog(OFConstantString *_Nonnull, ...);
+# ifdef __cplusplus
+}
+# endif
 # define OFEnsure(cond)							\
 	do {								\
 		if OF_UNLIKELY (!(cond)) {				\
 			OFLog(@"Failed to ensure condition in "		\
 			    @__FILE__ ":%d: " @#cond, __LINE__);	\

Index: src/runtime/ObjFWRT.h
==================================================================
--- src/runtime/ObjFWRT.h
+++ src/runtime/ObjFWRT.h
@@ -614,14 +614,14 @@
 extern void objc_setTaggedPointerSecret(uintptr_t secret);
 
 /**
  * @brief Registers a class for tagged pointers.
  *
- * @param class The class to register for tagged pointers
+ * @param class_ The class to register for tagged pointers
  * @return The tagged pointer ID for the registered class
  */
-extern int objc_registerTaggedPointerClass(Class _Nonnull class);
+extern int objc_registerTaggedPointerClass(Class _Nonnull class_);
 
 /**
  * @brief Returns whether the specified object is a tagged pointer.
  *
  * @param object The object to inspect
@@ -638,15 +638,15 @@
 extern uintptr_t object_getTaggedPointerValue(id _Nonnull object);
 
 /**
  * @brief Creates a new tagged pointer.
  *
- * @param class The tag ID for the tagged pointer class to use
+ * @param class_ The tag ID for the tagged pointer class to use
  * @param value The value the tagged pointer should have
  * @return A tagged pointer, or `nil` if it could not be created
  */
-extern id _Nullable objc_createTaggedPointer(int class, uintptr_t value);
+extern id _Nullable objc_createTaggedPointer(int class_, uintptr_t value);
 
 /*
  * Used by the compiler, but can also be called manually.
  *
  * These declarations are also required to prevent Clang's implicit