diff --git a/src/configure.c b/src/configure.c
index 66fe1a9..73a75b1 100644
--- a/src/configure.c
+++ b/src/configure.c
@@ -133,7 +133,9 @@ const struct ExtensionType _sExtensionType[] =
 	{ "cxx",	OT_CXX_SOURCE		},
 	{ "c++",	OT_CXX_SOURCE		},
 	{ "asm",	OT_ASM_SOURCE		},
+	{ "s",		OT_ASM_SOURCE		},
 	{ "S",		OT_ASM_SOURCE		},
+	{ "sx",		OT_ASM_SOURCE		},
 	{ "m",		OT_OBJC_SOURCE		},
 	{ "mm",		OT_OBJCXX_SOURCE	},
 	{ "v",		OT_VERILOG_SOURCE	},