diff --git a/libraries/classes/Import.php b/libraries/classes/Import.php
index b09e1e320d..d401defe02 100644
--- a/libraries/classes/Import.php
+++ b/libraries/classes/Import.php
@@ -587,6 +587,7 @@ class Import
      *
      * @return array Contains the precision, scale, and full size
      *                representation of the given decimal cell
+     * @psalm-return array{int,int,string}
      */
     public function getDecimalSize(string $cell): array
     {
@@ -710,15 +711,19 @@ class Import
                  * The last cumulative type was DECIMAL
                  */
                 $size = $this->getDecimalSize($cell);
+                $m = $size[self::M];
+                $d = $size[self::D];
 
                 $oldM = $this->getDecimalPrecision($lastCumulativeSize);
                 $oldD = $this->getDecimalScale($lastCumulativeSize);
 
                 /* New val if M or D is greater than current largest */
-                if ($size[self::M] > $oldM || $size[self::D] > $oldD) {
-                    /* Take the largest of both types */
-                    return (string) (($size[self::M] > $oldM ? $size[self::M] : $oldM)
-                        . ',' . ($size[self::D] > $oldD ? $size[self::D] : $oldD));
+                if ($m - $d > $oldM - $oldD || $d > $oldD) {
+                    // Widen type to fit current cell
+                    $newD = $oldD > $d ? $oldD : $d;
+                    $newM = ($oldM - $oldD > $m - $d ? $oldM - $oldD : $m - $d) + $newD;
+
+                    return $newM . ',' . $newD;
                 }
 
                 return $lastCumulativeSize;
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 58bd12e21c..27f5b0eb67 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -20522,7 +20522,7 @@ parameters:
 
 		-
 			message: "#^Casting to string something that's already string\\.$#"
-			count: 4
+			count: 3
 			path: libraries/classes/Import.php
 
 		-
@@ -20570,21 +20570,11 @@ parameters:
 			count: 1
 			path: libraries/classes/Import.php
 
-		-
-			message: "#^Method PhpMyAdmin\\\\Import\\:\\:detectSize\\(\\) should return int\\|string but returns mixed\\.$#"
-			count: 3
-			path: libraries/classes/Import.php
-
 		-
 			message: "#^Method PhpMyAdmin\\\\Import\\:\\:executeQuery\\(\\) has parameter \\$sqlData with no value type specified in iterable type array\\.$#"
 			count: 1
 			path: libraries/classes/Import.php
 
-		-
-			message: "#^Method PhpMyAdmin\\\\Import\\:\\:getDecimalSize\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: libraries/classes/Import.php
-
 		-
 			message: "#^Method PhpMyAdmin\\\\Import\\:\\:getLocalFiles\\(\\) has parameter \\$importList with no value type specified in iterable type array\\.$#"
 			count: 1
diff --git a/psalm-baseline.xml b/psalm-baseline.xml
index 5950f31017..a55969acd5 100644
--- a/psalm-baseline.xml
+++ b/psalm-baseline.xml
@@ -7838,14 +7838,11 @@
       <code>$sql_query</code>
       <code>$table</code>
     </MixedAssignment>
-    <MixedInferredReturnType occurrences="1">
-      <code>string|int</code>
-    </MixedInferredReturnType>
     <MixedMethodCall occurrences="2">
       <code>getExtension</code>
       <code>getProperties</code>
     </MixedMethodCall>
-    <MixedOperand occurrences="19">
+    <MixedOperand occurrences="16">
       <code>$complete_query</code>
       <code>$display_query</code>
       <code>$executed_queries</code>
@@ -7855,9 +7852,6 @@
       <code>$read_multiply</code>
       <code>$size</code>
       <code>$size</code>
-      <code>$size[self::D]</code>
-      <code>$size[self::D] &gt; $oldD ? $size[self::D] : $oldD</code>
-      <code>$size[self::M] &gt; $oldM ? $size[self::M] : $oldM</code>
       <code>$skip_queries</code>
       <code>$sqlData['valid_queries']</code>
       <code>$sqlData['valid_queries']</code>
@@ -7866,11 +7860,6 @@
       <code>$sql_query</code>
       <code>$timestamp</code>
     </MixedOperand>
-    <MixedReturnStatement occurrences="3">
-      <code>$size[self::FULL]</code>
-      <code>$size[self::FULL]</code>
-      <code>$size[self::M]</code>
-    </MixedReturnStatement>
     <PossiblyFalseOperand occurrences="3">
       <code>$decPos</code>
       <code>strpos($lastCumulativeSize, ',')</code>
@@ -7890,7 +7879,7 @@
     <PossiblyNullArrayAccess occurrences="1">
       <code>$additionalSql[$i]</code>
     </PossiblyNullArrayAccess>
-    <RedundantCast occurrences="4">
+    <RedundantCast occurrences="3">
       <code>(string) $cell</code>
       <code>(string) $cell</code>
       <code>(string) $cell</code>
diff --git a/test/classes/ImportTest.php b/test/classes/ImportTest.php
index 71cd8d06d9..b09ebc2d9e 100644
--- a/test/classes/ImportTest.php
+++ b/test/classes/ImportTest.php
@@ -455,6 +455,45 @@ class ImportTest extends AbstractTestCase
         return $data;
     }
 
+    /**
+     * Test for detectSize
+     *
+     * @param string|int $lastCumulativeSize Last cumulative column size
+     * @param int|null   $lastCumulativeType Last cumulative column type (NONE or VARCHAR or DECIMAL or INT or BIGINT)
+     * @param int        $currentCellType    Type of the current cell (NONE or VARCHAR or DECIMAL or INT or BIGINT)
+     * @param string     $cell               The current cell
+     *
+     * @dataProvider provTestDetectSize
+     */
+    public function testDetectSize(
+        string $expected,
+        $lastCumulativeSize,
+        ?int $lastCumulativeType,
+        int $currentCellType,
+        string $cell
+    ): void {
+        $actual = $this->import->detectSize($lastCumulativeSize, $lastCumulativeType, $currentCellType, $cell);
+        self::assertSame($expected, $actual);
+    }
+
+    /**
+     * Data provider for testDetectSize
+     *
+     * @return array<array{string,string|int,int,int,string}>
+     */
+    public function provTestDetectSize(): array
+    {
+        return [
+            [
+                '8,3',
+                '7,2',
+                Import::DECIMAL,
+                Import::DECIMAL,
+                '11.555',
+            ],
+        ];
+    }
+
     /**
      * Test for checkIfRollbackPossible
      */