diff --git a/math/stp/Makefile b/math/stp/Makefile
--- a/math/stp/Makefile
+++ b/math/stp/Makefile
@@ -1,6 +1,6 @@
 PORTNAME=	stp
 DISTVERSION=	2.3.3
-PORTREVISION=	11
+PORTREVISION=	12
 PORTEPOCH=	1
 CATEGORIES=	math
 
@@ -11,9 +11,6 @@
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
-BROKEN_aarch64=		fails to link: missing sbrk
-BROKEN_riscv64=		fails to link: missing sbrk
-
 LIB_DEPENDS=	libboost_program_options.so:devel/boost-libs \
 		libminisat.so:math/minisat \
 		libcryptominisat5.so:math/cryptominisat
diff --git a/math/stp/files/patch-tools_stp_main__common.cpp b/math/stp/files/patch-tools_stp_main__common.cpp
new file mode 100644
--- /dev/null
+++ b/math/stp/files/patch-tools_stp_main__common.cpp
@@ -0,0 +1,45 @@
+--- tools/stp/main_common.cpp.orig
++++ tools/stp/main_common.cpp
+@@ -27,16 +27,8 @@
+ #include "stp/Parser/parser.h"
+ #include "stp/cpp_interface.h"
+ 
+-//for srbk() function
+-#if !defined(__MINGW32__) && !defined(__MINGW64__) && !defined(_MSC_VER)
+-#include <unistd.h>
+-#endif
+-
+ extern void errorHandler(const char* error_msg);
+ 
+-// Amount of memory to ask for at beginning of main.
+-extern const intptr_t INITIAL_MEMORY_PREALLOCATION_SIZE;
+-
+ using namespace stp;
+ using std::unique_ptr;
+ using std::cout;
+@@ -49,9 +41,6 @@
+   exit(-1);
+ }
+ 
+-// Amount of memory to ask for at beginning of main.
+-const intptr_t INITIAL_MEMORY_PREALLOCATION_SIZE = 4000000;
+-
+ Main::Main() : onePrintBack(false)
+ {
+   bm = NULL;
+@@ -62,15 +51,6 @@
+ 
+   // Register the error handler
+   vc_error_hdlr = errorHandler;
+-
+-#if !defined(__MINGW32__) && !defined(__MINGW64__) && !defined(_MSC_VER)
+-  // Grab some memory from the OS upfront to reduce system time when
+-  // individual hash tables are being allocated
+-  if (sbrk(INITIAL_MEMORY_PREALLOCATION_SIZE) == ((void*)-1))
+-  {
+-    FatalError("Initial allocation of memory failed.");
+-  }
+-#endif
+ 
+   bm = new STPMgr();
+   GlobalParserBM = bm;