diff --git a/src/crypto/CryptonightR_JIT.c b/src/crypto/CryptonightR_JIT.c
index 68258a959..ee8f3f36f 100644
--- a/src/crypto/CryptonightR_JIT.c
+++ b/src/crypto/CryptonightR_JIT.c
@@ -4,6 +4,9 @@
 #include <string.h>
 #include <stdio.h>
 #include <unistd.h>
+#if !(defined(_MSC_VER) || defined(__MINGW32__))
+#include <sys/mman.h>
+#endif
 
 #include "int-util.h"
 #include "hash-ops.h"
@@ -58,6 +61,11 @@ int v4_generate_JIT_code(const struct V4_Instruction* code, v4_random_math_JIT_f
 	uint8_t* JIT_code = (uint8_t*) buf;
 	const uint8_t* JIT_code_end = JIT_code + buf_size;
 
+#if !(defined(_MSC_VER) || defined(__MINGW32__))
+	if (mprotect((void*)buf, buf_size, PROT_READ | PROT_WRITE))
+		return 1;
+#endif
+
 	APPEND_CODE(prologue, sizeof(prologue));
 
 	uint32_t prev_rot_src = 0xFFFFFFFFU;
@@ -101,6 +109,11 @@ int v4_generate_JIT_code(const struct V4_Instruction* code, v4_random_math_JIT_f
 
 	APPEND_CODE(epilogue, sizeof(epilogue));
 
+#if !(defined(_MSC_VER) || defined(__MINGW32__))
+	if (mprotect((void*)buf, buf_size, PROT_READ | PROT_EXEC))
+		return 1;
+#endif
+
 	__builtin___clear_cache((char*)buf, (char*)JIT_code);
 
 	return 0;
diff --git a/src/crypto/slow-hash.c b/src/crypto/slow-hash.c
index 6bdc1b28c..a9c776be5 100644
--- a/src/crypto/slow-hash.c
+++ b/src/crypto/slow-hash.c
@@ -756,10 +756,10 @@ void slow_hash_allocate_state(void)
 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
   defined(__DragonFly__) || defined(__NetBSD__)
     hp_state = mmap(0, MEMORY, PROT_READ | PROT_WRITE,
-                    MAP_PRIVATE | MAP_ANON, 0, 0);
+                    MAP_PRIVATE | MAP_ANON, -1, 0);
 #else
     hp_state = mmap(0, MEMORY, PROT_READ | PROT_WRITE,
-                    MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, 0, 0);
+                    MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
 #endif
     if(hp_state == MAP_FAILED)
         hp_state = NULL;
@@ -778,11 +778,16 @@ void slow_hash_allocate_state(void)
 #else
 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
   defined(__DragonFly__) || defined(__NetBSD__)
-    hp_jitfunc_memory = mmap(0, 4096 + 4095, PROT_READ | PROT_WRITE | PROT_EXEC,
-                    MAP_PRIVATE | MAP_ANON, 0, 0);
+#ifdef __NetBSD__
+#define RESERVED_FLAGS PROT_MPROTECT(PROT_EXEC)
 #else
-    hp_jitfunc_memory = mmap(0, 4096 + 4095, PROT_READ | PROT_WRITE | PROT_EXEC,
-                    MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
+#define RESERVED_FLAGS 0
+#endif
+    hp_jitfunc_memory = mmap(0, 4096 + 4096, PROT_READ | PROT_WRITE | RESERVED_FLAGS,
+                    MAP_PRIVATE | MAP_ANON, -1, 0);
+#else
+    hp_jitfunc_memory = mmap(0, 4096 + 4096, PROT_READ | PROT_WRITE | PROT_EXEC,
+                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 #endif
     if(hp_jitfunc_memory == MAP_FAILED)
         hp_jitfunc_memory = NULL;
@@ -794,9 +799,6 @@ void slow_hash_allocate_state(void)
         hp_jitfunc_memory = malloc(4096 + 4095);
     }
     hp_jitfunc = (v4_random_math_JIT_func)((size_t)(hp_jitfunc_memory + 4095) & ~4095);
-#if !(defined(_MSC_VER) || defined(__MINGW32__))
-    mprotect(hp_jitfunc, 4096, PROT_READ | PROT_WRITE | PROT_EXEC);
-#endif
 }
 
 /**