diff --git a/include/pybind11/detail/common.h b/include/pybind11/detail/common.h
index a5b47c9..d5bf318 100644
--- a/include/pybind11/detail/common.h
+++ b/include/pybind11/detail/common.h
@@ -164,7 +164,9 @@
 #define PYBIND11_STR_TYPE ::pybind11::str
 #define PYBIND11_BOOL_ATTR "__bool__"
 #define PYBIND11_NB_BOOL(ptr) ((ptr)->nb_bool)
+// Providing a separate declaration to make Clang's -Wmissing-prototypes happy
 #define PYBIND11_PLUGIN_IMPL(name) \
+    extern "C" PYBIND11_EXPORT PyObject *PyInit_##name();   \
     extern "C" PYBIND11_EXPORT PyObject *PyInit_##name()
 
 #else
@@ -188,8 +190,10 @@
 #define PYBIND11_STR_TYPE ::pybind11::bytes
 #define PYBIND11_BOOL_ATTR "__nonzero__"
 #define PYBIND11_NB_BOOL(ptr) ((ptr)->nb_nonzero)
+// Providing a separate PyInit decl to make Clang's -Wmissing-prototypes happy
 #define PYBIND11_PLUGIN_IMPL(name) \
     static PyObject *pybind11_init_wrapper();               \
+    extern "C" PYBIND11_EXPORT void init##name();           \
     extern "C" PYBIND11_EXPORT void init##name() {          \
         (void)pybind11_init_wrapper();                      \
     }                                                       \