diff --git a/srcpkgs/firefox/patches/fix-musl.patch b/srcpkgs/firefox/patches/fix-musl.patch
new file mode 100644
index 0000000000..c32921d39e
--- /dev/null
+++ b/srcpkgs/firefox/patches/fix-musl.patch
@@ -0,0 +1,11 @@
+--- tools/profiler/core/platform.h.orig
++++ tools/profiler/core/platform.h
+@@ -56,7 +56,7 @@
+
+ // We need a definition of gettid(), but glibc doesn't provide a
+ // wrapper for it.
+-#if defined(__GLIBC__)
++#if defined(__linux__)
+ #include <unistd.h>
+ #include <sys/syscall.h>
+ static inline pid_t gettid()