diff --git a/app/build.gradle b/app/build.gradle
index 8d33323f3..1b745f0b6 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -186,7 +186,7 @@ ext {
 }
 
 dependencies {
-    implementation "io.github.wulkanowy:sdk:1.7.5"
+    implementation "io.github.wulkanowy:sdk:2840d9d6d0"
 
     coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.1.8'
 
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryAdapter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryAdapter.kt
index 082c847e5..8dcade56e 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryAdapter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryAdapter.kt
@@ -10,6 +10,7 @@ import io.github.wulkanowy.data.db.entities.GradeSummary
 import io.github.wulkanowy.data.repositories.PreferencesRepository
 import io.github.wulkanowy.databinding.ItemGradeSummaryBinding
 import io.github.wulkanowy.databinding.ScrollableHeaderGradeSummaryBinding
+import io.github.wulkanowy.sdk.scrapper.grades.isGradeValid
 import io.github.wulkanowy.utils.calcFinalAverage
 import java.util.Locale
 import javax.inject.Inject
@@ -61,7 +62,7 @@ class GradeSummaryAdapter @Inject constructor(
         if (items.isEmpty()) return
 
         val context = binding.root.context
-        val finalItemsCount = items.count { it.finalGrade.matches("[0-6][+-]?".toRegex()) }
+        val finalItemsCount = items.count { isGradeValid(it.finalGrade) }
         val calculatedItemsCount = items.count { value -> value.average != 0.0 }
         val allItemsCount = items.count { !it.subject.equals("zachowanie", true) }
         val finalAverage = items.calcFinalAverage(
diff --git a/app/src/main/java/io/github/wulkanowy/utils/GradeExtension.kt b/app/src/main/java/io/github/wulkanowy/utils/GradeExtension.kt
index ff65d6376..61924d4e9 100644
--- a/app/src/main/java/io/github/wulkanowy/utils/GradeExtension.kt
+++ b/app/src/main/java/io/github/wulkanowy/utils/GradeExtension.kt
@@ -4,6 +4,7 @@ import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.Grade
 import io.github.wulkanowy.data.db.entities.GradeSummary
 import io.github.wulkanowy.data.enums.GradeColorTheme
+import io.github.wulkanowy.sdk.scrapper.grades.getGradeValueWithModifier
 import io.github.wulkanowy.sdk.scrapper.grades.isGradeValid
 
 fun List<Grade>.calcAverage(isOptionalArithmeticAverage: Boolean): Double {
@@ -20,20 +21,15 @@ fun List<Grade>.calcAverage(isOptionalArithmeticAverage: Boolean): Double {
 }
 
 fun List<GradeSummary>.calcFinalAverage(plusModifier: Double, minusModifier: Double) = asSequence()
-    .mapNotNull {
-        if (it.finalGrade.matches("[0-6][+-]?".toRegex())) {
-            when {
-                it.finalGrade.endsWith('+') -> {
-                    it.finalGrade.removeSuffix("+").toDouble() + plusModifier
-                }
-                it.finalGrade.endsWith('-') -> {
-                    it.finalGrade.removeSuffix("-").toDouble() - minusModifier
-                }
-                else -> {
-                    it.finalGrade.toDouble()
-                }
-            }
-        } else null
+    .mapNotNull { summary ->
+        val (gradeValue, gradeModifier) = getGradeValueWithModifier(summary.finalGrade)
+        if (gradeValue == null || gradeModifier == null) return@mapNotNull null
+
+        when {
+            gradeModifier > 0 -> gradeValue + plusModifier
+            gradeModifier < 0 -> gradeValue - minusModifier
+            else -> gradeValue + 0.0
+        }
     }
     .average()
     .let { if (it.isNaN()) 0.0 else it }