diff --git a/pandas/_libs/src/headers/portable.h b/pandas/_libs/src/headers/portable.h
index 3464fba963a5e..91b4702d32452 100644
--- a/pandas/_libs/src/headers/portable.h
+++ b/pandas/_libs/src/headers/portable.h
@@ -1,16 +1,10 @@
 #ifndef _PANDAS_PORTABLE_H_
 #define _PANDAS_PORTABLE_H_
 
-// To get `strdup` from strings.h
-#ifndef _XOPEN_SOURCE
-#define _XOPEN_SOURCE 600
-#endif
-
 #include <string.h>
 
 #if defined(_MSC_VER)
 #define strcasecmp( s1, s2 ) _stricmp( s1, s2 )
-#define strdup _strdup
 #endif
 
 // GH-23516 - works around locale perf issues
diff --git a/pandas/_libs/src/ujson/lib/ultrajsondec.c b/pandas/_libs/src/ujson/lib/ultrajsondec.c
index c7779b8b428ae..5347db1655669 100644
--- a/pandas/_libs/src/ujson/lib/ultrajsondec.c
+++ b/pandas/_libs/src/ujson/lib/ultrajsondec.c
@@ -1174,15 +1174,21 @@ JSOBJ JSON_DecodeObject(JSONObjectDecoder *dec, const char *buffer,
     ds.dec = dec;
 
     locale = setlocale(LC_NUMERIC, NULL);
+    if (!locale) {
+        return SetError(&ds, -1, "setlocale call failed");
+    }
+
     if (strcmp(locale, "C")) {
-        locale = strdup(locale);
-        if (!locale) {
-            return SetError(&ds, -1, "Could not reserve memory block");
+        size_t len = strlen(locale) + 1;
+        char *saved_locale = malloc(len);
+        if (saved_locale == NULL) {
+          return SetError(&ds, -1, "Could not reserve memory block");
         }
+        memcpy(saved_locale, locale, len);
         setlocale(LC_NUMERIC, "C");
         ret = decode_any(&ds);
-        setlocale(LC_NUMERIC, locale);
-        free(locale);
+        setlocale(LC_NUMERIC, saved_locale);
+        free(saved_locale);
     } else {
         ret = decode_any(&ds);
     }
diff --git a/pandas/_libs/src/ujson/lib/ultrajsonenc.c b/pandas/_libs/src/ujson/lib/ultrajsonenc.c
index 5d90710441a94..a74d505b0d0ec 100644
--- a/pandas/_libs/src/ujson/lib/ultrajsonenc.c
+++ b/pandas/_libs/src/ujson/lib/ultrajsonenc.c
@@ -1176,16 +1176,23 @@ char *JSON_EncodeObject(JSOBJ obj, JSONObjectEncoder *enc, char *_buffer,
     enc->offset = enc->start;
 
     locale = setlocale(LC_NUMERIC, NULL);
+    if (!locale) {
+        SetError(NULL, enc, "setlocale call failed");
+        return NULL;
+    }
+
     if (strcmp(locale, "C")) {
-        locale = strdup(locale);
-        if (!locale) {
-            SetError(NULL, enc, "Could not reserve memory block");
-            return NULL;
+        size_t len = strlen(locale) + 1;
+        char *saved_locale = malloc(len);
+        if (saved_locale == NULL) {
+          SetError(NULL, enc, "Could not reserve memory block");
+          return NULL;
         }
+        memcpy(saved_locale, locale, len);
         setlocale(LC_NUMERIC, "C");
         encode(obj, enc, NULL, 0);
-        setlocale(LC_NUMERIC, locale);
-        free(locale);
+        setlocale(LC_NUMERIC, saved_locale);
+        free(saved_locale);
     } else {
         encode(obj, enc, NULL, 0);
     }
diff --git a/setup.py b/setup.py
index 05d4407c7e959..02b91cbb0d9b4 100755
--- a/setup.py
+++ b/setup.py
@@ -649,7 +649,7 @@ def srcpath(name=None, suffix=".pyx", subdir="src"):
         "pandas/_libs/src/datetime",
         numpy.get_include(),
     ],
-    extra_compile_args=(["-D_GNU_SOURCE"] + extra_compile_args),
+    extra_compile_args=(extra_compile_args),
     extra_link_args=extra_link_args,
     define_macros=macros,
 )