diff --git a/libc/stdio/fmt.c b/libc/stdio/fmt.c
index 8658a62e4..a866b196f 100644
--- a/libc/stdio/fmt.c
+++ b/libc/stdio/fmt.c
@@ -1145,6 +1145,8 @@ int __fmt(void *fn, void *arg, const char *format, va_list va, int *wrote) {
           s = s0 =
               gdtoa(fpb.fpi, fpb.ex, fpb.bits, &fpb.kind, 3, prec, &decpt, &se);
         }
+        if (s0 == NULL)
+          return -1;
         if (decpt == 9999 || decpt == -32768) {
         FormatDecpt9999Or32768:
           if (s0)
@@ -1258,6 +1260,8 @@ int __fmt(void *fn, void *arg, const char *format, va_list va, int *wrote) {
           s = s0 = gdtoa(fpb.fpi, fpb.ex, fpb.bits, &fpb.kind, prec ? 2 : 0,
                          prec, &decpt, &se);
         }
+        if (s0 == NULL)
+          return -1;
         if (decpt == 9999 || decpt == -32768)
           goto FormatDecpt9999Or32768;
         c = se - s;
@@ -1304,6 +1308,8 @@ int __fmt(void *fn, void *arg, const char *format, va_list va, int *wrote) {
           s = s0 = gdtoa(fpb.fpi, fpb.ex, fpb.bits, &fpb.kind, prec ? 2 : 0,
                          prec, &decpt, &se);
         }
+        if (s0 == NULL)
+          return -1;
         if (decpt == 9999 || decpt == -32768)
           goto FormatDecpt9999Or32768;
       FormatExpo:
diff --git a/test/libc/stdio/snprintf_enomem_test.c b/test/libc/stdio/snprintf_enomem_test.c
new file mode 100644
index 000000000..57e305487
--- /dev/null
+++ b/test/libc/stdio/snprintf_enomem_test.c
@@ -0,0 +1,61 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2024 Gabriel Ravier                                                │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/struct/rlimit.h"
+#include "libc/errno.h"
+#include "libc/stdio/stdio.h"
+#include "libc/sysv/consts/rlim.h"
+#include "libc/sysv/consts/rlimit.h"
+#include "libc/testlib/testlib.h"
+
+static void limit_memory_to_1mb() {
+  struct rlimit limit = {};
+  ASSERT_GE(getrlimit(RLIMIT_AS, &limit), 0);
+
+  if (limit.rlim_max > 1000000 || limit.rlim_max == RLIM_INFINITY) {
+    limit.rlim_max = 1000000;
+    limit.rlim_cur = limit.rlim_max;
+    ASSERT_GE(setrlimit(RLIMIT_AS, &limit), 0);
+  }
+}
+
+static void check_double_format_enomem(const char *fmt) {
+  errno = 0;
+  int result = printf(fmt, 1.0);
+  ASSERT_LE(result, 0);
+  ASSERT_EQ(errno, ENOMEM);
+}
+
+static void check_long_double_format_enomem(const char *fmt) {
+  errno = 0;
+  int result = printf(fmt, 1.0L);
+  ASSERT_LE(result, 0);
+  ASSERT_EQ(errno, ENOMEM);
+}
+
+TEST(snprintf, enomemFloat) {
+  limit_memory_to_1mb();
+
+  check_double_format_enomem("%.1000000f");
+  check_double_format_enomem("%.1000000g");
+  check_double_format_enomem("%.1000000e");
+
+  check_long_double_format_enomem("%.1000000Lf");
+  check_long_double_format_enomem("%.1000000Lg");
+  check_long_double_format_enomem("%.1000000Le");
+}
diff --git a/third_party/gdtoa/dmisc.c b/third_party/gdtoa/dmisc.c
index a0871ddec..8f5b55a84 100644
--- a/third_party/gdtoa/dmisc.c
+++ b/third_party/gdtoa/dmisc.c
@@ -49,6 +49,8 @@ __gdtoa_rv_alloc(int i, ThInfo **PTI)
 	     j <<= 1)
 		k++;
 	r = (int *)__gdtoa_Balloc(k, PTI);
+	if (r == NULL)
+		return NULL;
 	*r = k;
 	return (char *)(r + 1);
 }
diff --git a/third_party/gdtoa/dtoa.c b/third_party/gdtoa/dtoa.c
index 6982c73b0..a6eafc70e 100644
--- a/third_party/gdtoa/dtoa.c
+++ b/third_party/gdtoa/dtoa.c
@@ -246,6 +246,9 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
 			i = 1;
 	}
 	s = s0 = __gdtoa_rv_alloc(i, &TI);
+	if (s0 == NULL)
+		goto ret1;
+
 	if (mode > 1 && Rounding != 1)
 		leftright = 0;
 	if (ilim >= 0 && ilim <= Quick_max && try_quick) {
@@ -614,7 +617,8 @@ retc:
 		--s;
 ret1:
 	__gdtoa_Bfree(b, &TI);
-	*s = 0;
+	if (s != NULL)
+		*s = 0;
 	*decpt = k + 1;
 	if (rve)
 		*rve = s;
diff --git a/third_party/gdtoa/gdtoa.c b/third_party/gdtoa/gdtoa.c
index 67199c53d..74ba329a7 100644
--- a/third_party/gdtoa/gdtoa.c
+++ b/third_party/gdtoa/gdtoa.c
@@ -286,6 +286,8 @@ gdtoa(const FPI *fpi, int be, ULong *bits, int *kindp, int mode, int ndigits, in
 			i = 1;
 	}
 	s = s0 = __gdtoa_rv_alloc(i, &TI);
+	if (s0 == NULL)
+		goto ret1;
 	if (mode <= 1)
 		rdir = 0;
 	else if ( (rdir = fpi->rounding - 1) !=0) {
@@ -673,10 +675,12 @@ ret:
 		__gdtoa_Bfree(mhi, &TI);
 	}
 ret1:
-	while(s > s0 && s[-1] == '0')
-		--s;
+	if (s != NULL)
+		while(s > s0 && s[-1] == '0')
+			--s;
 	__gdtoa_Bfree(b, &TI);
-	*s = 0;
+	if (s != NULL)
+		*s = 0;
 	*decpt = k + 1;
 	if (rve)
 		*rve = s;
diff --git a/third_party/gdtoa/misc.c b/third_party/gdtoa/misc.c
index 845f73223..0ff9afa12 100644
--- a/third_party/gdtoa/misc.c
+++ b/third_party/gdtoa/misc.c
@@ -129,12 +129,16 @@ __gdtoa_Balloc(int k, ThInfo **PTI)
 	} else {
 		x = 1 << k;
 		rv = malloc(sizeof(Bigint) + (x-1)*sizeof(ULong));
+		if (rv == NULL)
+			goto ret;
 		rv->k = k;
 		rv->maxwds = x;
 	}
+	rv->sign = rv->wds = 0;
+
+ret:
 	if (TI == &TI0)
 		__gdtoa_unlock();
-	rv->sign = rv->wds = 0;
 	return rv;
 }