diff --git a/src/Type/ValueSet.php b/src/Type/ValueSet.php
index 9f5a54343e9..69f61442070 100644
--- a/src/Type/ValueSet.php
+++ b/src/Type/ValueSet.php
@@ -948,7 +948,7 @@ private function calculateShift(string $operator, self $right, PhpVersion $phpVe
 
 	/**
 	 * Operands with more pairs of constants than are computed one by one become the
-	 * type all their constants are: int, float, string or null; anything else can
+	 * type all their constants are: int, float, int|float, string or null; anything else can
 	 * only be an error.
 	 *
 	 * @return array{self, self}
@@ -976,12 +976,13 @@ private function generalize(): self
 		$hasStrings = $this->strings !== null;
 		$hasNumbers = $this->numbers !== null && !$this->numbers->isEmpty();
 		if (!$hasBooleans && !$hasStrings && !$this->null && $hasNumbers) {
-			if ($this->numbers->getFloatIntervals() === [] && !$this->numbers->hasNan()) {
-				return self::createNumbers(new NumberSet([[null, null]], [], false));
-			}
-			if ($this->numbers->getIntegerIntervals() === []) {
-				return self::createNumbers(new NumberSet([], [[-INF, INF]], true));
-			}
+			$hasFloats = $this->numbers->getFloatIntervals() !== [] || $this->numbers->hasNan();
+
+			return self::createNumbers(new NumberSet(
+				$this->numbers->getIntegerIntervals() !== [] ? [[null, null]] : [],
+				$hasFloats ? [[-INF, INF]] : [],
+				$hasFloats,
+			));
 		}
 		if (!$hasBooleans && !$hasNumbers && !$this->null && $hasStrings) {
 			return self::createStrings(new StringType());
diff --git a/tests/PHPStan/Analyser/nsrt/bug-15670.php b/tests/PHPStan/Analyser/nsrt/bug-15670.php
new file mode 100644
index 00000000000..b1a2bf0aa3b
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-15670.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace Bug15670;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @param 0|0.01|0.02|0.03|0.04|0.05|0.06|0.07|0.08|0.09|0.10|0.11 $a
+ * @param 0.1|0.2|0.3|0.4|0.5|0.6|0.7|0.8|0.9|1.0|1.1 $b
+ * @param 0|1|2|3|4|5|6|7|8|9|10|0.5 $c
+ * @param 1|2|3|4|5|6|7|8|9|10|11 $d
+ */
+function mixedIntFloat($a, $b, $c, $d): void
+{
+	assertType('float', $a + $b);
+	assertType('float|int', $c + $d);
+	assertType('float|int', $c * $d);
+}
+
+final class Foo
+{
+
+	private const WEIGHTS = [1 => 0.0761, 2 => 0.0720, 3 => 0.0811, 4 => 0.0812, 5 => 0.0813, 6 => 0.0814, 7 => 0.0815, 8 => 0.0816, 9 => 0.0817, 10 => 0.0818, 11 => 0.0819, 12 => 0.1290];
+
+	/** @param list<int<0, 12>> $months */
+	public function doFoo(array $months): void
+	{
+		$weight = 0;
+		foreach ($months as $month) {
+			if ($month === 0) {
+				break;
+			}
+			$weight += self::WEIGHTS[$month] ?? 0.0;
+		}
+		assertType('0|float', $weight);
+	}
+
+}
diff --git a/turbo-ext/src/ValueSet.cpp b/turbo-ext/src/ValueSet.cpp
index 4f8db4095f8..3b426d0eca7 100644
--- a/turbo-ext/src/ValueSet.cpp
+++ b/turbo-ext/src/ValueSet.cpp
@@ -1172,13 +1172,13 @@ class ValueSetOps
 		bool hasNumbers = !numbersEmpty(s.numbers());
 		if (!hasBooleans && !hasStrings && !s.null_() && hasNumbers) {
 			NumbersView n(s.numbers());
-			if (n.floatCount() == 0 && !n.nan()) return createNumbersOf(anyInteger());
-			if (n.integerCount() == 0) {
-				NumberSetData anyFloat;
-				anyFloat.floatIntervals.push_back({-HUGE_VAL, HUGE_VAL});
-				anyFloat.nan = true;
-				return createNumbersOf(anyFloat);
+			bool hasFloats = n.floatCount() != 0 || n.nan();
+			NumberSetData generalized = n.integerCount() != 0 ? anyInteger() : NumberSetData();
+			if (hasFloats) {
+				generalized.floatIntervals.push_back({-HUGE_VAL, HUGE_VAL});
+				generalized.nan = true;
 			}
+			return createNumbersOf(generalized);
 		}
 		if (!hasBooleans && !hasNumbers && !s.null_() && hasStrings) {
 			IETR_VAL(stringType, newStringType());