diff --git a/src/Compilation.zig b/src/Compilation.zig
index 1fddda42f91c26d5256975aeadf0ea46922336b5..1b32a80279299d9b1a4796fc3a8eb6f50f78db4e 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -2012,7 +2012,8 @@ pub fn hasAsmExt(filename: []const u8) bool {
 pub fn hasSharedLibraryExt(filename: []const u8) bool {
     if (mem.endsWith(u8, filename, ".so") or
         mem.endsWith(u8, filename, ".dll") or
-        mem.endsWith(u8, filename, ".dylib"))
+        mem.endsWith(u8, filename, ".dylib") or
+        mem.endsWith(u8, filename, ".tbd"))
     {
         return true;
     }
diff --git a/src/main.zig b/src/main.zig
index 58f8c0be448d47668537f2d7423fade5891c7e83..ff3ef7c1c3b0eaca26a5ea722fb72d4d14ac7085 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -221,6 +221,7 @@ const usage_build_generic =
     \\                     .so    ELF shared object (dynamic link)
     \\                    .dll    Windows Dynamic Link Library
     \\                  .dylib    MACH-O (macOS) dynamic library
+    \\                    .tbd    (macOS) text-based dylib definition
     \\                      .s    Target-specific assembly source code
     \\                      .S    Assembly with C preprocessor (requires LLVM extensions)
     \\                      .c    C source code (requires LLVM extensions)