diff --git a/configure.ac b/configure.ac
index 2ad2190275c..aa5456e8c56 100644
--- a/configure.ac
+++ b/configure.ac
@@ -434,7 +434,6 @@ netinet/in.h \
 alloca.h \
 arpa/inet.h \
 arpa/nameser.h \
-assert.h \
 crypt.h \
 dns.h \
 fcntl.h \
@@ -477,7 +476,6 @@ utime.h \
 sys/utsname.h \
 sys/ipc.h \
 dlfcn.h \
-assert.h \
 tmmintrin.h \
 nmmintrin.h \
 immintrin.h
diff --git a/ext/bcmath/libbcmath/src/add.c b/ext/bcmath/libbcmath/src/add.c
index ade5b5969a0..d41ea01914c 100644
--- a/ext/bcmath/libbcmath/src/add.c
+++ b/ext/bcmath/libbcmath/src/add.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/compare.c b/ext/bcmath/libbcmath/src/compare.c
index 6217ef1af33..ced7ec19167 100644
--- a/ext/bcmath/libbcmath/src/compare.c
+++ b/ext/bcmath/libbcmath/src/compare.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/debug.c b/ext/bcmath/libbcmath/src/debug.c
index 0ff7d652cd1..b711c06143b 100644
--- a/ext/bcmath/libbcmath/src/debug.c
+++ b/ext/bcmath/libbcmath/src/debug.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/div.c b/ext/bcmath/libbcmath/src/div.c
index df5de299190..a8039f2b767 100644
--- a/ext/bcmath/libbcmath/src/div.c
+++ b/ext/bcmath/libbcmath/src/div.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/divmod.c b/ext/bcmath/libbcmath/src/divmod.c
index 08c2f8a2a2d..6ee6c255cb8 100644
--- a/ext/bcmath/libbcmath/src/divmod.c
+++ b/ext/bcmath/libbcmath/src/divmod.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/doaddsub.c b/ext/bcmath/libbcmath/src/doaddsub.c
index cef0fdbf1ba..dc0ba0614bf 100644
--- a/ext/bcmath/libbcmath/src/doaddsub.c
+++ b/ext/bcmath/libbcmath/src/doaddsub.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/init.c b/ext/bcmath/libbcmath/src/init.c
index bd73da2a9d7..227a34fadfe 100644
--- a/ext/bcmath/libbcmath/src/init.c
+++ b/ext/bcmath/libbcmath/src/init.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/int2num.c b/ext/bcmath/libbcmath/src/int2num.c
index a8965f6040e..12a3342c397 100644
--- a/ext/bcmath/libbcmath/src/int2num.c
+++ b/ext/bcmath/libbcmath/src/int2num.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/nearzero.c b/ext/bcmath/libbcmath/src/nearzero.c
index 1f2f0708ccf..041c7e149dc 100644
--- a/ext/bcmath/libbcmath/src/nearzero.c
+++ b/ext/bcmath/libbcmath/src/nearzero.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/neg.c b/ext/bcmath/libbcmath/src/neg.c
index 619a59bb05c..8c009055989 100644
--- a/ext/bcmath/libbcmath/src/neg.c
+++ b/ext/bcmath/libbcmath/src/neg.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/num2long.c b/ext/bcmath/libbcmath/src/num2long.c
index be84986d236..2cef6791c4a 100644
--- a/ext/bcmath/libbcmath/src/num2long.c
+++ b/ext/bcmath/libbcmath/src/num2long.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/num2str.c b/ext/bcmath/libbcmath/src/num2str.c
index 7316d32a14a..742d3278e73 100644
--- a/ext/bcmath/libbcmath/src/num2str.c
+++ b/ext/bcmath/libbcmath/src/num2str.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/outofmem.c b/ext/bcmath/libbcmath/src/outofmem.c
index 7c675096865..e1e3f5317f8 100644
--- a/ext/bcmath/libbcmath/src/outofmem.c
+++ b/ext/bcmath/libbcmath/src/outofmem.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/output.c b/ext/bcmath/libbcmath/src/output.c
index 9fbca0f4c4a..e172662002e 100644
--- a/ext/bcmath/libbcmath/src/output.c
+++ b/ext/bcmath/libbcmath/src/output.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/raise.c b/ext/bcmath/libbcmath/src/raise.c
index c7838be5975..4b938cb3b34 100644
--- a/ext/bcmath/libbcmath/src/raise.c
+++ b/ext/bcmath/libbcmath/src/raise.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/raisemod.c b/ext/bcmath/libbcmath/src/raisemod.c
index a3154b55cd8..9b371cc4e0d 100644
--- a/ext/bcmath/libbcmath/src/raisemod.c
+++ b/ext/bcmath/libbcmath/src/raisemod.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/rmzero.c b/ext/bcmath/libbcmath/src/rmzero.c
index 1b81601b201..4751099d240 100644
--- a/ext/bcmath/libbcmath/src/rmzero.c
+++ b/ext/bcmath/libbcmath/src/rmzero.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/sqrt.c b/ext/bcmath/libbcmath/src/sqrt.c
index 265d75b5fba..ffb19fc5198 100644
--- a/ext/bcmath/libbcmath/src/sqrt.c
+++ b/ext/bcmath/libbcmath/src/sqrt.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/str2num.c b/ext/bcmath/libbcmath/src/str2num.c
index 62544de80ec..abf68eb1e56 100644
--- a/ext/bcmath/libbcmath/src/str2num.c
+++ b/ext/bcmath/libbcmath/src/str2num.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/sub.c b/ext/bcmath/libbcmath/src/sub.c
index b63f1bc90ac..86c876d1c63 100644
--- a/ext/bcmath/libbcmath/src/sub.c
+++ b/ext/bcmath/libbcmath/src/sub.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/bcmath/libbcmath/src/zero.c b/ext/bcmath/libbcmath/src/zero.c
index ffb54975468..6f0e93a0263 100644
--- a/ext/bcmath/libbcmath/src/zero.c
+++ b/ext/bcmath/libbcmath/src/zero.c
@@ -31,7 +31,6 @@
 
 #include <config.h>
 #include <stdio.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/ext/mbstring/libmbfl/config.h.in b/ext/mbstring/libmbfl/config.h.in
index c30fa09f4ae..28bb935f937 100644
--- a/ext/mbstring/libmbfl/config.h.in
+++ b/ext/mbstring/libmbfl/config.h.in
@@ -1,8 +1,5 @@
 /* config.h.in.  Generated from configure.in by autoheader.  */
 
-/* Define to 1 if you have the <assert.h> header file. */
-#undef HAVE_ASSERT_H
-
 /* Define to 1 if you have the <dlfcn.h> header file. */
 #undef HAVE_DLFCN_H
 
diff --git a/ext/mbstring/libmbfl/config.h.w32 b/ext/mbstring/libmbfl/config.h.w32
index 14393a07412..4ec537284d5 100644
--- a/ext/mbstring/libmbfl/config.h.w32
+++ b/ext/mbstring/libmbfl/config.h.w32
@@ -1,6 +1,5 @@
 #define HAVE_STDIO_H 1
 #define HAVE_STDLIB_H 1
-#define HAVE_ASSERT_H 1
 #define HAVE_MEMORY_H 1
 /* #undef HAVE_STRINGS_H */
 #define HAVE_STRING_H 1
diff --git a/ext/standard/strnatcmp.c b/ext/standard/strnatcmp.c
index 64ff8fc37d3..bcbd556afe3 100644
--- a/ext/standard/strnatcmp.c
+++ b/ext/standard/strnatcmp.c
@@ -24,7 +24,6 @@
 
 #include <ctype.h>
 #include <string.h>
-#include <assert.h>
 #include <stdio.h>
 
 #include "php.h"
diff --git a/main/php.h b/main/php.h
index 697d3ff935c..4134f7b3d42 100644
--- a/main/php.h
+++ b/main/php.h
@@ -123,7 +123,6 @@ typedef int pid_t;
 # endif
 #endif
 
-#if HAVE_ASSERT_H
 #if PHP_DEBUG
 #undef NDEBUG
 #else
@@ -132,9 +131,6 @@ typedef int pid_t;
 #endif
 #endif
 #include <assert.h>
-#else /* HAVE_ASSERT_H */
-#define assert(expr) ((void) (0))
-#endif /* HAVE_ASSERT_H */
 
 #define APACHE 0
 
diff --git a/main/php_syslog.c b/main/php_syslog.c
index dd16f05217c..2170ac70be0 100644
--- a/main/php_syslog.c
+++ b/main/php_syslog.c
@@ -18,7 +18,6 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <assert.h>
 #include <stdlib.h>
 #include "php.h"
 #include "php_syslog.h"
diff --git a/win32/build/config.w32.h.in b/win32/build/config.w32.h.in
index 4a510ea6b44..3275552b46b 100644
--- a/win32/build/config.w32.h.in
+++ b/win32/build/config.w32.h.in
@@ -95,7 +95,6 @@
 #define HAVE_TEMPNAM 1
 #define HAVE_UTIME 1
 #undef HAVE_DIRENT_H
-#define HAVE_ASSERT_H 1
 #define HAVE_FCNTL_H 1
 #define HAVE_GRP_H 0
 #undef HAVE_PWD_H