diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 335d1ab..b16de04 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -154,6 +154,16 @@ ksp {
     arg("room.schemaLocation", "$projectDir/schemas")
 }
 
+// Compile against the library versions the APK actually ships. floret-kit's
+// `implementation` deps reach only the runtime classpath, so a newer material3
+// there once won at runtime while the app compiled against an older one, and
+// a removed ButtonGroup overload crashed every tab with NoSuchMethodError (#10).
+androidComponents {
+    onVariants { variant ->
+        variant.compileConfiguration.shouldResolveConsistentlyWith(variant.runtimeConfiguration)
+    }
+}
+
 kotlin {
     compilerOptions {
         jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17
diff --git a/app/src/main/java/de/jeanlucmakiola/clockula/ui/alarms/RepeatDaySelector.kt b/app/src/main/java/de/jeanlucmakiola/clockula/ui/alarms/RepeatDaySelector.kt
index 22b7598..6a1916e 100644
--- a/app/src/main/java/de/jeanlucmakiola/clockula/ui/alarms/RepeatDaySelector.kt
+++ b/app/src/main/java/de/jeanlucmakiola/clockula/ui/alarms/RepeatDaySelector.kt
@@ -7,7 +7,6 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.Text
 import androidx.compose.material3.ToggleButton
-import androidx.compose.material3.ToggleButtonDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
@@ -59,7 +58,6 @@ internal fun RepeatDaySelector(
                 ToggleButton(
                     checked = day in repeatDays,
                     onCheckedChange = { onDayToggled(day) },
-                    shapes = ToggleButtonDefaults.shapes(),
                     modifier = Modifier
                         .weight(1f)
                         .semantics { contentDescription = full },
diff --git a/app/src/main/java/de/jeanlucmakiola/clockula/ui/stopwatch/StopwatchReadoutPanel.kt b/app/src/main/java/de/jeanlucmakiola/clockula/ui/stopwatch/StopwatchReadoutPanel.kt
index 129e75f..a3ae23d 100644
--- a/app/src/main/java/de/jeanlucmakiola/clockula/ui/stopwatch/StopwatchReadoutPanel.kt
+++ b/app/src/main/java/de/jeanlucmakiola/clockula/ui/stopwatch/StopwatchReadoutPanel.kt
@@ -11,7 +11,7 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.material3.Button
-import androidx.compose.material3.ButtonGroup
+import androidx.compose.material3.ButtonGroupDefaults
 import androidx.compose.material3.CircularWavyProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.FilledTonalButton
@@ -180,7 +180,7 @@ private fun StopwatchControls(
 ) {
     val lapLimit = stringResource(R.string.stopwatch_lap_limit)
 
-    ButtonGroup(modifier = modifier) {
+    Row(modifier = modifier, horizontalArrangement = ButtonGroupDefaults.HorizontalArrangement) {
         val primaryInteraction = remember { MutableInteractionSource() }
         val primary = when (mode) {
             StopwatchState.RUNNING -> R.string.stopwatch_pause to onPause
diff --git a/app/src/main/java/de/jeanlucmakiola/clockula/ui/timers/TimerRow.kt b/app/src/main/java/de/jeanlucmakiola/clockula/ui/timers/TimerRow.kt
index 73095ba..d99eb4e 100644
--- a/app/src/main/java/de/jeanlucmakiola/clockula/ui/timers/TimerRow.kt
+++ b/app/src/main/java/de/jeanlucmakiola/clockula/ui/timers/TimerRow.kt
@@ -18,7 +18,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.rounded.Close
-import androidx.compose.material3.ButtonGroup
+import androidx.compose.material3.ButtonGroupDefaults
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.FilledTonalIconButton
@@ -248,7 +248,7 @@ private fun TimerControls(
         TimerMode.IDLE -> R.string.timer_add_minute to onAddMinute
     }
 
-    ButtonGroup(modifier = modifier) {
+    Row(modifier = modifier, horizontalArrangement = ButtonGroupDefaults.HorizontalArrangement) {
         val actions = buildList {
             add(primary)
             if (mode == TimerMode.RUNNING || mode == TimerMode.PAUSED) {
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index b939e75..258f005 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -3,15 +3,15 @@ agp = "9.2.1"
 kotlin = "2.3.21"
 ksp = "2.3.9"
 hilt = "2.59.2"
-coreKtx = "1.19.0"
-appcompat = "1.7.1"
+coreKtx = "1.19.1"
+appcompat = "1.8.0"
 lifecycleRuntime = "2.10.0"
 activityCompose = "1.13.0"
-composeBom = "2026.05.01"
+composeBom = "2026.09.00"
 # Material 3 Expressive APIs currently live only in the 1.5 alpha line.
 # Pin explicitly to override the BOM (which ships stable 1.4.0).
 # Re-evaluate when 1.5.0 stable lands.
-material3 = "1.5.0-alpha21"
+material3 = "1.5.0-alpha29"
 datastore = "1.2.1"
 # SAF directory writing for export/backup (DocumentFile).
 documentfile = "1.1.0"