diff --git a/libc/calls/pledge-linux.c b/libc/calls/pledge-linux.c
index 2bb52c038..d36684bfd 100644
--- a/libc/calls/pledge-linux.c
+++ b/libc/calls/pledge-linux.c
@@ -1641,7 +1641,6 @@ static privileged void AllowMmapExec(struct Filter *f) {
 //
 //   - MAP_LOCKED   (0x02000)
 //   - MAP_NONBLOCK (0x10000)
-//   - MAP_HUGETLB  (0x40000)
 //
 static privileged void AllowMmapNoexec(struct Filter *f) {
   static const struct sock_filter fragment[] = {
@@ -1650,7 +1649,7 @@ static privileged void AllowMmapNoexec(struct Filter *f) {
       /*L2*/ BPF_STMT(BPF_ALU | BPF_AND | BPF_K, ~(PROT_READ | PROT_WRITE)),
       /*L3*/ BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, 8 - 4),
       /*L4*/ BPF_STMT(BPF_LD | BPF_W | BPF_ABS, OFF(args[3])),  // flags
-      /*L5*/ BPF_STMT(BPF_ALU | BPF_AND | BPF_K, 0x52000),
+      /*L5*/ BPF_STMT(BPF_ALU | BPF_AND | BPF_K, 0x12000),
       /*L6*/ BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, 1),
       /*L7*/ BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ALLOW),
       /*L8*/ BPF_STMT(BPF_LD | BPF_W | BPF_ABS, OFF(nr)),
diff --git a/libc/intrin/describemapflags.c b/libc/intrin/describemapflags.c
index 7c207d2e3..5ff541b37 100644
--- a/libc/intrin/describemapflags.c
+++ b/libc/intrin/describemapflags.c
@@ -30,6 +30,7 @@ const char *(DescribeMapFlags)(char buf[64], int x) {
       {MAP_SHARED, "SHARED"},                    //
       {MAP_FIXED, "FIXED"},                      //
       {MAP_FIXED_NOREPLACE, "FIXED_NOREPLACE"},  //
+      {MAP_HUGETLB, "HUGETLB"},                  //
       {MAP_CONCEAL, "CONCEAL"},                  //
       {MAP_LOCKED, "LOCKED"},                    //
       {MAP_NORESERVE, "NORESERVE"},              //
diff --git a/libc/sysv/consts.sh b/libc/sysv/consts.sh
index 1242f1e4a..696b94040 100755
--- a/libc/sysv/consts.sh
+++ b/libc/sysv/consts.sh
@@ -230,6 +230,7 @@ syscon	mmap	MAP_NORESERVE				0x00004000		0x00004000		0x00000040		0x00000040		0
 syscon	mmap	MAP_POPULATE				0x00008000		0x00008000		0			0			0x00040000		0			0			0			# MAP_PREFAULT_READ on FreeBSD; can avoid madvise(MADV_WILLNEED) on private file mapping
 syscon	mmap	MAP_NONBLOCK				0x00010000		0x00010000		0			0			0			0			0			0
 syscon	mmap	MAP_SYNC				0x00080000		0x00080000		0			0			0			0			0			0			# perform synchronous page faults for mapping (Linux 4.15+)
+syscon	mmap	MAP_HUGETLB				0x00040000		-1			-1			-1			-1			-1			-1			-1			# make it inherit across execve()
 syscon	mmap	MAP_INHERIT				-1			-1			-1			-1			-1			-1			0x00000080		-1			# make it inherit across execve()
 syscon	mmap	MAP_HASSEMAPHORE			0			0			0x00000200		0x00000200		0x00000200		0			0x00000200		0			# does it matter on x86?
 syscon	mmap	MAP_NOSYNC				0			0			0			0			0x00000800		0			0			0			# flush to physical media only when necessary rather than gratuitously; be sure to use write() rather than ftruncate() with this!
diff --git a/libc/sysv/consts/MAP_HUGETLB.S b/libc/sysv/consts/MAP_HUGETLB.S
new file mode 100644
index 000000000..5062efe09
--- /dev/null
+++ b/libc/sysv/consts/MAP_HUGETLB.S
@@ -0,0 +1,2 @@
+#include "libc/sysv/consts/syscon.internal.h"
+.syscon mmap,MAP_HUGETLB,0x00040000,-1,-1,-1,-1,-1,-1,-1
diff --git a/libc/sysv/consts/map.h b/libc/sysv/consts/map.h
index 04008f4cd..c1e3fbc58 100644
--- a/libc/sysv/consts/map.h
+++ b/libc/sysv/consts/map.h
@@ -13,6 +13,7 @@ extern const int MAP_FILE;
 extern const int MAP_FIXED;
 extern const int MAP_FIXED_NOREPLACE;
 extern const int MAP_HASSEMAPHORE;
+extern const int MAP_HUGETLB;
 extern const int MAP_INHERIT;
 extern const int MAP_JIT;
 extern const int MAP_LOCKED;
diff --git a/third_party/dlmalloc/platform.inc b/third_party/dlmalloc/platform.inc
index 25c80f416..d7733a657 100644
--- a/third_party/dlmalloc/platform.inc
+++ b/third_party/dlmalloc/platform.inc
@@ -111,7 +111,7 @@
 #if (MORECORE_CONTIGUOUS || defined(WIN32))
 #define DEFAULT_GRANULARITY (0)  /* 0 means to compute in init_mparams */
 #else   /* MORECORE_CONTIGUOUS */
-#define DEFAULT_GRANULARITY ((size_t)64U * (size_t)1024U)
+#define DEFAULT_GRANULARITY ((size_t)256U * (size_t)1024U)
 #endif  /* MORECORE_CONTIGUOUS */
 #endif  /* DEFAULT_GRANULARITY */
 #ifndef DEFAULT_TRIM_THRESHOLD