diff --git a/third_party/musl/hsearch.c b/third_party/musl/hsearch.c
index c8936f5f28e..1945fb2eac0 100644
--- a/third_party/musl/hsearch.c
+++ b/third_party/musl/hsearch.c
@@ -27,7 +27,6 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/mem/mem.h"
 #include "libc/str/str.h"
-#define _GNU_SOURCE
 #include "third_party/musl/search.h"
 
 asm(".ident\t\"\\n\\n\
diff --git a/third_party/musl/search.h b/third_party/musl/search.h
index 50d263df4e1..c3385243a6d 100644
--- a/third_party/musl/search.h
+++ b/third_party/musl/search.h
@@ -1,5 +1,6 @@
 #ifndef COSMOPOLITAN_THIRDPARTY_MUSL_SEARCH_H
 #define COSMOPOLITAN_THIRDPARTY_MUSL_SEARCH_H
+/* clang-format off */
 
 typedef enum { FIND, ENTER } ACTION;
 typedef enum { preorder, postorder, endorder, leaf } VISIT;
@@ -13,7 +14,7 @@ int hcreate(size_t);
 void hdestroy(void);
 ENTRY *hsearch(ENTRY, ACTION);
 
-#ifdef _GNU_SOURCE
+#if defined(_GNU_SOURCE) || defined(_COSMO_SOURCE)
 struct hsearch_data {
 	struct __tab *__tab;
 	unsigned int __unused1;
@@ -38,7 +39,7 @@ void *tfind(const void *, void *const *, int(*)(const void *, const void *));
 void *tsearch(const void *, void **, int (*)(const void *, const void *));
 void twalk(const void *, void (*)(const void *, VISIT, int));
 
-#ifdef _GNU_SOURCE
+#if defined(_GNU_SOURCE) || defined(_COSMO_SOURCE)
 struct qelem {
 	struct qelem *q_forw, *q_back;
 	char q_data[1];
diff --git a/third_party/musl/tdelete.c b/third_party/musl/tdelete.c
index 731d94fb748..28ae5588b52 100644
--- a/third_party/musl/tdelete.c
+++ b/third_party/musl/tdelete.c
@@ -26,8 +26,7 @@
 │                                                                              │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/mem/mem.h"
-#include "third_party/musl/search.h"
-#include "third_party/musl/tsearch.h"
+#include "third_party/musl/tsearch.internal.h"
 
 asm(".ident\t\"\\n\\n\
 Musl libc (MIT License)\\n\
diff --git a/third_party/musl/tdestroy.c b/third_party/musl/tdestroy.c
index ff2baca8988..a23b73ce74b 100644
--- a/third_party/musl/tdestroy.c
+++ b/third_party/musl/tdestroy.c
@@ -26,9 +26,7 @@
 │                                                                              │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/mem/mem.h"
-#define _GNU_SOURCE
-#include "third_party/musl/search.h"
-#include "third_party/musl/tsearch.h"
+#include "third_party/musl/tsearch.internal.h"
 
 asm(".ident\t\"\\n\\n\
 Musl libc (MIT License)\\n\
diff --git a/third_party/musl/tfind.c b/third_party/musl/tfind.c
index 166a4713184..2e064c4b3e2 100644
--- a/third_party/musl/tfind.c
+++ b/third_party/musl/tfind.c
@@ -25,8 +25,7 @@
 │  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                      │
 │                                                                              │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "third_party/musl/search.h"
-#include "third_party/musl/tsearch.h"
+#include "third_party/musl/tsearch.internal.h"
 
 asm(".ident\t\"\\n\\n\
 Musl libc (MIT License)\\n\
diff --git a/third_party/musl/tsearch.c b/third_party/musl/tsearch.c
index 0b932e93d46..fbeb9775c27 100644
--- a/third_party/musl/tsearch.c
+++ b/third_party/musl/tsearch.c
@@ -27,8 +27,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/mem/mem.h"
 #include "libc/str/str.h"
-#include "third_party/musl/search.h"
-#include "third_party/musl/tsearch.h"
+#include "third_party/musl/tsearch.internal.h"
 
 asm(".ident\t\"\\n\\n\
 Musl libc (MIT License)\\n\
diff --git a/third_party/musl/tsearch.h b/third_party/musl/tsearch.internal.h
similarity index 100%
rename from third_party/musl/tsearch.h
rename to third_party/musl/tsearch.internal.h
diff --git a/third_party/musl/twalk.c b/third_party/musl/twalk.c
index b36591bb653..30856610908 100644
--- a/third_party/musl/twalk.c
+++ b/third_party/musl/twalk.c
@@ -25,8 +25,7 @@
 │  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                      │
 │                                                                              │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "third_party/musl/search.h"
-#include "third_party/musl/tsearch.h"
+#include "third_party/musl/tsearch.internal.h"
 
 asm(".ident\t\"\\n\\n\
 Musl libc (MIT License)\\n\