diff --git a/ext/standard/formatted_print.c b/ext/standard/formatted_print.c
index b0fbfcc89099f..298a07ae47a77 100644
--- a/ext/standard/formatted_print.c
+++ b/ext/standard/formatted_print.c
@@ -266,6 +266,19 @@ php_sprintf_appenddouble(zend_string **buffer, size_t *pos,
 			s = php_conv_fp((fmt == 'f')?'F':fmt, number, 0, precision,
 						(fmt == 'f')?LCONV_DECIMAL_POINT:'.',
 						&is_negative, &num_buf[1], &s_len);
+			/* Prevent negative sign when value rounds to zero (GH-12237) */
+			if (is_negative) {
+				double rounded;
+				if (fmt == 'f' || fmt == 'F') {
+					double factor = pow(10.0, (double)precision);
+					rounded = round(fabs(number) * factor) / factor;
+				} else {
+					rounded = fabs(number);
+				}
+				if (rounded == 0.0) {
+					is_negative = false;
+				}
+			}
 			if (is_negative) {
 				num_buf[0] = '-';
 				s = num_buf;
diff --git a/ext/standard/tests/strings/gh12237.phpt b/ext/standard/tests/strings/gh12237.phpt
new file mode 100644
index 0000000000000..652070a50d92c
--- /dev/null
+++ b/ext/standard/tests/strings/gh12237.phpt
@@ -0,0 +1,107 @@
+--TEST--
+GH-12237 (printf/sprintf should not produce negative zero)
+--FILE--
+<?php
+
+// Basic case from the bug report
+echo "-- Basic case --\n";
+var_dump(sprintf('%.2f', -0.001));
+var_dump(sprintf('%.2f', -0.0));
+
+// Various precisions where the value rounds to zero
+echo "-- Precisions rounding to zero --\n";
+var_dump(sprintf('%.0f', -0.1));
+var_dump(sprintf('%.0f', -0.0));
+var_dump(sprintf('%.1f', -0.04));
+var_dump(sprintf('%.1f', -0.001));
+var_dump(sprintf('%.2f', -0.004));
+var_dump(sprintf('%.2f', -0.001));
+var_dump(sprintf('%.3f', -0.0004));
+var_dump(sprintf('%.3f', -0.0001));
+var_dump(sprintf('%.4f', -0.00004));
+var_dump(sprintf('%.4f', -0.00001));
+
+// Values that should remain negative (do NOT round to zero)
+echo "-- Should stay negative --\n";
+var_dump(sprintf('%.2f', -0.01));
+var_dump(sprintf('%.2f', -0.1));
+var_dump(sprintf('%.2f', -1.5));
+var_dump(sprintf('%.1f', -0.1));
+var_dump(sprintf('%.0f', -1.0));
+
+// Uppercase F format
+echo "-- Uppercase F --\n";
+var_dump(sprintf('%.2F', -0.001));
+var_dump(sprintf('%.2F', -0.01));
+
+// Explicit positive sign should show + when value rounds to zero
+echo "-- Explicit sign --\n";
+var_dump(sprintf('%+.2f', -0.001));
+var_dump(sprintf('%+.2f', 0.001));
+var_dump(sprintf('%+.2f', -0.01));
+
+// printf output (not just sprintf)
+echo "-- printf --\n";
+printf('%.2f', -0.001);
+echo "\n";
+printf('%.2f', -0.01);
+echo "\n";
+
+// Consistency with number_format
+echo "-- number_format consistency --\n";
+var_dump(number_format(-0.001, 2));
+var_dump(number_format(-0.01, 2));
+
+// Very small negative values that round to zero
+echo "-- Very small negatives --\n";
+var_dump(sprintf('%.2f', -1e-10));
+var_dump(sprintf('%.2f', -PHP_FLOAT_EPSILON));
+var_dump(sprintf('%.2f', -1e-100));
+
+// Padding and width
+echo "-- Padding --\n";
+var_dump(sprintf('%08.2f', -0.001));
+var_dump(sprintf('%08.2f', -0.01));
+
+?>
+--EXPECT--
+-- Basic case --
+string(4) "0.00"
+string(4) "0.00"
+-- Precisions rounding to zero --
+string(1) "0"
+string(1) "0"
+string(3) "0.0"
+string(3) "0.0"
+string(4) "0.00"
+string(4) "0.00"
+string(5) "0.000"
+string(5) "0.000"
+string(6) "0.0000"
+string(6) "0.0000"
+-- Should stay negative --
+string(5) "-0.01"
+string(5) "-0.10"
+string(5) "-1.50"
+string(4) "-0.1"
+string(2) "-1"
+-- Uppercase F --
+string(4) "0.00"
+string(5) "-0.01"
+-- Explicit sign --
+string(5) "+0.00"
+string(5) "+0.00"
+string(5) "-0.01"
+-- printf --
+0.00
+-0.01
+-- number_format consistency --
+string(4) "0.00"
+string(5) "-0.01"
+-- Very small negatives --
+string(4) "0.00"
+string(4) "0.00"
+string(4) "0.00"
+-- Padding --
+string(8) "00000.00"
+string(8) "-0000.01"
diff --git a/ext/standard/tests/strings/sprintf_variation9.phpt b/ext/standard/tests/strings/sprintf_variation9.phpt
index e2f4d113245ab..3394d4a4e9fa3 100644
--- a/ext/standard/tests/strings/sprintf_variation9.phpt
+++ b/ext/standard/tests/strings/sprintf_variation9.phpt
@@ -336,15 +336,15 @@ string(8) "0.000000"
 string(30) "                      0.000000"
 
 -- Iteration 26 --
-string(9) "-0.000000"
-string(9) "-0.000000"
-string(10) " -0.000000"
-string(10) "-0.000000 "
-string(10) "	-0.000000"
-string(10) "
--0.000000"
-string(9) "-0.000000"
-string(30) "                     -0.000000"
+string(8) "0.000000"
+string(8) "0.000000"
+string(9) " 0.000000"
+string(9) "0.000000 "
+string(9) "	0.000000"
+string(9) "
+0.000000"
+string(8) "0.000000"
+string(30) "                      0.000000"
 
 -- Iteration 27 --
 string(50) "5000000000000000069686058479707049565356032.000000"
@@ -380,13 +380,13 @@ string(8) "0.000000"
 string(30) "                      0.000000"
 
 -- Iteration 30 --
-string(9) "-0.000000"
-string(9) "-0.000000"
-string(10) " -0.000000"
-string(10) "-0.000000 "
-string(10) "	-0.000000"
-string(10) "
--0.000000"
-string(9) "-0.000000"
-string(30) "                     -0.000000"
+string(8) "0.000000"
+string(8) "0.000000"
+string(9) " 0.000000"
+string(9) "0.000000 "
+string(9) "	0.000000"
+string(9) "
+0.000000"
+string(8) "0.000000"
+string(30) "                      0.000000"
 Done
diff --git a/ext/standard/tests/strings/vprintf_variation5.phpt b/ext/standard/tests/strings/vprintf_variation5.phpt
index b09acb7877396..50c66c02fde1b 100644
--- a/ext/standard/tests/strings/vprintf_variation5.phpt
+++ b/ext/standard/tests/strings/vprintf_variation5.phpt
@@ -64,8 +64,8 @@ int(28)
 int(54)
 
 -- Iteration 4 --
-200000.0000 0.0000     -200000.000000 -0.0000
-int(45)
+200000.0000 0.0000     -200000.000000 0.0000
+int(44)
 
 -- Iteration 5 --
 20000.000000 -1999999999999999879418332743206357172224.000000 0.000000 20000000000000000000.000000