diff --git a/Makefile b/Makefile
index 4334761a4..4623a23c4 100644
--- a/Makefile
+++ b/Makefile
@@ -95,6 +95,20 @@ MK_CFLAGS   = $(CPPFLAGS) $(OPT) -std=c11   -fPIC
 MK_CXXFLAGS = $(CPPFLAGS) $(OPT) -std=c++11 -fPIC
 MK_LDFLAGS  =
 
+# clock_gettime came in POSIX.1b (1993)
+# CLOCK_MONOTONIC came in POSIX.1-2001 / SUSv3 as optional
+# posix_memalign came in POSIX.1-2001 / SUSv3
+# M_PI is an XSI extension since POSIX.1-2001 / SUSv3, came in XPG1 (1985)
+MK_CFLAGS   += -D_XOPEN_SOURCE=600
+MK_CXXFLAGS += -D_XOPEN_SOURCE=600
+
+# Data types, macros and functions related to controlling CPU affinity and
+# some memory allocation are available on Linux through GNU extensions in libc
+ifeq ($(UNAME_S),Linux)
+	MK_CFLAGS   += -D_GNU_SOURCE
+	MK_CXXFLAGS += -D_GNU_SOURCE
+endif
+
 ifdef LLAMA_DEBUG
 	MK_CFLAGS   += -O0 -g
 	MK_CXXFLAGS += -O0 -g
diff --git a/examples/beam-search/beam-search.cpp b/examples/beam-search/beam-search.cpp
index 4d021434b..6b31aea78 100644
--- a/examples/beam-search/beam-search.cpp
+++ b/examples/beam-search/beam-search.cpp
@@ -1,7 +1,3 @@
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
 #include "common.h"
 #include "llama.h"
 #include "build-info.h"
diff --git a/examples/embd-input/embd-input-lib.cpp b/examples/embd-input/embd-input-lib.cpp
index 036bdb398..53076eb0f 100644
--- a/examples/embd-input/embd-input-lib.cpp
+++ b/examples/embd-input/embd-input-lib.cpp
@@ -1,8 +1,3 @@
-// Defines sigaction on msys:
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
 #include "embd-input.h"
 
 #include <cassert>
diff --git a/examples/main/main.cpp b/examples/main/main.cpp
index 9201b53bd..e6c70cc63 100644
--- a/examples/main/main.cpp
+++ b/examples/main/main.cpp
@@ -1,8 +1,3 @@
-// Defines sigaction on msys:
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
 #include "common.h"
 
 #include "console.h"
diff --git a/examples/simple/simple.cpp b/examples/simple/simple.cpp
index 4ee85faca..ba5de0cc6 100644
--- a/examples/simple/simple.cpp
+++ b/examples/simple/simple.cpp
@@ -1,7 +1,3 @@
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
 #include "build-info.h"
 
 #include "common.h"
diff --git a/examples/speculative/speculative.cpp b/examples/speculative/speculative.cpp
index c6211ac79..822d7b529 100644
--- a/examples/speculative/speculative.cpp
+++ b/examples/speculative/speculative.cpp
@@ -1,7 +1,3 @@
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
 #include "build-info.h"
 
 #include "common.h"
diff --git a/ggml-alloc.c b/ggml-alloc.c
index c1939a4b7..695bbfe10 100644
--- a/ggml-alloc.c
+++ b/ggml-alloc.c
@@ -1,8 +1,3 @@
-// defines MAP_ANONYMOUS
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
 #include "ggml-alloc.h"
 #include "ggml.h"
 #include <assert.h>
diff --git a/ggml.c b/ggml.c
index 50adf18ec..1ea4e5a4c 100644
--- a/ggml.c
+++ b/ggml.c
@@ -1,4 +1,3 @@
-#define _GNU_SOURCE // Defines CLOCK_MONOTONIC on Linux
 #define _CRT_SECURE_NO_DEPRECATE // Disables ridiculous "unsafe" warnigns on Windows
 
 #include "ggml.h"
diff --git a/llama.cpp b/llama.cpp
index 2c9071a8f..74ffbc8d1 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -1,8 +1,3 @@
-// Defines fileno on msys:
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
 #include "llama.h"
 
 #include "ggml.h"