diff --git a/pkgs/by-name/li/libfyaml/package.nix b/pkgs/by-name/li/libfyaml/package.nix
index 26cc0461020b..7a7e5dc089c6 100644
--- a/pkgs/by-name/li/libfyaml/package.nix
+++ b/pkgs/by-name/li/libfyaml/package.nix
@@ -34,6 +34,10 @@ stdenv.mkDerivation (finalAttrs: {
       url = "https://github.com/pantoniou/libfyaml/commit/9192deaac095f9881cc1e5756dede683f36b09d6.diff";
       hash = "sha256-cNL9wQtxIRg/ShZLJP4qHYNFRrYo9kRG+/U+3FiUeaI=";
     })
+    # On Darwin, AX_PTHREAD returns empty PTHREAD_LIBS with -pthread in PTHREAD_CFLAGS;
+    # don't force -lpthread when PTHREAD_CFLAGS already provides pthread support.
+    # Pending PR: https://github.com/pantoniou/libfyaml/pull/294
+    ./pthread-darwin.patch
   ];
 
   nativeBuildInputs = [
diff --git a/pkgs/by-name/li/libfyaml/pthread-darwin.patch b/pkgs/by-name/li/libfyaml/pthread-darwin.patch
new file mode 100644
index 000000000000..bada0d80d142
--- /dev/null
+++ b/pkgs/by-name/li/libfyaml/pthread-darwin.patch
@@ -0,0 +1,12 @@
+--- a/configure.ac
++++ b/configure.ac
+@@ -99,6 +99,7 @@
+ AX_PTHREAD([], [AC_MSG_ERROR("Missing required pthread support")])
+ 
+-# in some cases PTHREAD_LIBS is empty - force -lpthread */
+-if test "x$PTHREAD_LIBS" = "x"; then
++# In some cases PTHREAD_LIBS is empty; force -lpthread only when PTHREAD_CFLAGS
++# also provides no pthread support (e.g. on Darwin, -pthread in CFLAGS suffices).
++if test "x$PTHREAD_LIBS" = "x" && test "x$PTHREAD_CFLAGS" = "x"; then
+ 	PTHREAD_LIBS="-lpthread"
+ fi