diff --git a/pd/src/s_loader.c b/pd/src/s_loader.c
index 788f9cb2c90ac5723ba128924e323b1641731d9e..7a78aca8064c1f99366b1452656cc7f01ce1e8e7 100644
--- a/pd/src/s_loader.c
+++ b/pd/src/s_loader.c
@@ -38,23 +38,27 @@ a fat binary or an indication of the instruction set. */
 
 #ifdef __FreeBSD__
 static char sys_dllextent[] = ".b_i386", sys_dllextent2[] = ".pd_freebsd";
-#endif
-#ifdef __linux__
-#ifdef __x86_64__
-static char sys_dllextent[] = ".l_ia64", sys_dllextent2[] = ".pd_linux";
-#else
-static char sys_dllextent[] = ".l_i386", sys_dllextent2[] = ".pd_linux";
-#endif
-#endif
-#ifdef __APPLE__
-#ifndef MACOSX3
+#elif defined(__linux__) || defined(__FreeBSD_kernel__) || defined(__GNU__)
+static char sys_dllextent2[] = ".pd_linux";
+# ifdef __x86_64__
+static char sys_dllextent[] = ".l_ia64"; // this should be .l_x86_64 or .l_amd64
+# elif defined(__i386__) || defined(_M_IX86)
+static char sys_dllextent[] = ".l_i386";
+# elif defined(__arm__)
+static char sys_dllextent[] = ".l_arm";
+# else
+static char sys_dllextent[] = ".so";
+# endif
+#elif defined(__APPLE__)
+# ifndef MACOSX3
 static char sys_dllextent[] = ".d_fat", sys_dllextent2[] = ".pd_darwin";
-#else
+# else
 static char sys_dllextent[] = ".d_ppc", sys_dllextent2[] = ".pd_darwin";
-#endif
-#endif
-#ifdef MSW
+# endif
+#elif defined(_WIN32) || defined(__CYGWIN__)
 static char sys_dllextent[] = ".m_i386", sys_dllextent2[] = ".dll";
+#else
+static char sys_dllextent[] = ".so", sys_dllextent2[] = ".so";
 #endif
 
     /* maintain list of loaded modules to avoid repeating loads */