diff --git a/Sources/GhosttyTerminalView.swift b/Sources/GhosttyTerminalView.swift
index 259e40192c3a..1cc167b57e1d 100644
--- a/Sources/GhosttyTerminalView.swift
+++ b/Sources/GhosttyTerminalView.swift
@@ -2098,8 +2098,9 @@ class GhosttyApp {
                 return
             }
 
+            let fallbackShouldUseHostLayerBackground = usesHostLayerBackground(for: fallbackConfig)
             loadInlineGhosttyConfig(
-                "macos-background-from-layer = true",
+                "macos-background-from-layer = \(fallbackShouldUseHostLayerBackground)",
                 into: fallbackConfig,
                 prefix: "cmux-renderer-bg",
                 logLabel: "renderer background (fallback)"
@@ -2112,7 +2113,7 @@ class GhosttyApp {
             )
             loadCmuxOwnedGhosttyKeybindOverrides(fallbackConfig)
             let fallbackRenderingModeChanged = setUsesHostLayerBackground(
-                true,
+                fallbackShouldUseHostLayerBackground,
                 source: "initialize.fallbackConfig"
             )
             ghostty_config_finalize(fallbackConfig)
@@ -2248,15 +2249,17 @@ class GhosttyApp {
         }
         #endif
         loadCJKFontFallbackIfNeeded(config)
+        let shouldUseHostLayerBackground = usesHostLayerBackground(for: config)
         let renderingModeChanged = setUsesHostLayerBackground(
-            true,
+            shouldUseHostLayerBackground,
             source: "loadDefaultConfigFilesWithLegacyFallback"
         )
-        // Let cmux own the window-level backdrop once, while Ghostty keeps
-        // rendering text, cell backgrounds, and background images. This avoids
-        // separate translucent fills for terminal and chrome surfaces.
+        // Let Ghostty paint solid opaque terminal backgrounds so default cells
+        // and explicit ANSI background cells share one renderer/compositor path.
+        // Host-layer ownership remains required for translucent and blurred
+        // terminal backgrounds.
         loadInlineGhosttyConfig(
-            "macos-background-from-layer = true",
+            "macos-background-from-layer = \(shouldUseHostLayerBackground)",
             into: config,
             prefix: "cmux-renderer-bg",
             logLabel: "renderer background"
@@ -3214,10 +3217,7 @@ class GhosttyApp {
         let resolvedCursorText = ghosttyColorValue(from: config, key: "cursor-text", fallback: baseline.cursorTextColor)
         let resolvedSelectionBackground = ghosttyColorValue(from: config, key: "selection-background", fallback: baseline.selectionBackground)
         let resolvedSelectionForeground = ghosttyColorValue(from: config, key: "selection-foreground", fallback: baseline.selectionForeground)
-        var opacity = baseline.backgroundOpacity
-        let opacityKey = "background-opacity"
-        _ = ghostty_config_get(config, &opacity, opacityKey, UInt(opacityKey.lengthOfBytes(using: .utf8)))
-        opacity = min(1.0, max(0.0, opacity))
+        let opacity = defaultBackgroundOpacityValue(from: config)
         let backgroundBlur = defaultBackgroundBlurValue(from: config)
         applyDefaultBackground(
             color: resolvedColor,
@@ -3234,6 +3234,20 @@ class GhosttyApp {
         )
     }
 
+    private func defaultBackgroundOpacityValue(from config: ghostty_config_t) -> Double {
+        var opacity = Self.fallbackAppearanceConfig.backgroundOpacity
+        let key = "background-opacity"
+        _ = ghostty_config_get(config, &opacity, key, UInt(key.lengthOfBytes(using: .utf8)))
+        return Double(WindowAppearanceSnapshot.clampedOpacity(opacity))
+    }
+
+    private func usesHostLayerBackground(for config: ghostty_config_t) -> Bool {
+        WindowAppearanceSnapshot.usesHostLayerBackground(
+            backgroundOpacity: defaultBackgroundOpacityValue(from: config),
+            backgroundBlur: defaultBackgroundBlurValue(from: config)
+        )
+    }
+
     private func defaultBackgroundBlurValue(from config: ghostty_config_t) -> GhosttyBackgroundBlur {
         var value: Int16 = 0
         let key = "background-blur"
diff --git a/Sources/Windowing/WindowAppearanceSnapshot.swift b/Sources/Windowing/WindowAppearanceSnapshot.swift
index 2b809560fc92..c3eac3a914af 100644
--- a/Sources/Windowing/WindowAppearanceSnapshot.swift
+++ b/Sources/Windowing/WindowAppearanceSnapshot.swift
@@ -213,6 +213,11 @@ struct WindowGlassSettingsSnapshot {
 }
 
 struct WindowAppearanceSnapshot {
+    /// Treat opacity values within floating-point round-trip tolerance of 1.0
+    /// as opaque so user-configured `1.0` does not accidentally trigger host
+    /// ownership after Double/CGFloat conversions.
+    private static let opaqueBackgroundOwnershipThreshold: CGFloat = 0.999
+
     let terminalBackgroundColor: NSColor
     let terminalBackgroundOpacity: CGFloat
     let terminalBackgroundBlur: GhosttyBackgroundBlur
@@ -285,6 +290,28 @@ struct WindowAppearanceSnapshot {
         usesHostLayerBackground ? .windowHostBackdrop : .ghosttyRendererOwnedBackgroundImage
     }
 
+    static func usesHostLayerBackground(
+        backgroundOpacity: Double,
+        backgroundBlur: GhosttyBackgroundBlur
+    ) -> Bool {
+        if backgroundBlur != .disabled {
+            return true
+        }
+        return clampedOpacity(backgroundOpacity) < opaqueBackgroundOwnershipThreshold
+    }
+
+    static func terminalRenderingMode(
+        backgroundOpacity: Double,
+        backgroundBlur: GhosttyBackgroundBlur
+    ) -> GhosttyTerminalBackdropRenderingMode {
+        terminalRenderingMode(
+            usesHostLayerBackground: usesHostLayerBackground(
+                backgroundOpacity: backgroundOpacity,
+                backgroundBlur: backgroundBlur
+            )
+        )
+    }
+
     var compositedTerminalBackgroundColor: NSColor {
         terminalBackgroundColor.withAlphaComponent(terminalBackgroundOpacity)
     }
diff --git a/cmuxTests/WindowAppearanceSnapshotTests.swift b/cmuxTests/WindowAppearanceSnapshotTests.swift
index 0396108065ec..53d55a0406a0 100644
--- a/cmuxTests/WindowAppearanceSnapshotTests.swift
+++ b/cmuxTests/WindowAppearanceSnapshotTests.swift
@@ -110,6 +110,54 @@ final class WindowAppearanceSnapshotTests: XCTestCase {
         XCTAssertEqual(plan.windowBackgroundColor.hexString(includeAlpha: true), "#272822FF")
     }
 
+    func testOpaqueUnblurredTerminalBackgroundIsRendererOwned() {
+        let snapshot = makeSnapshot(
+            unifySurfaceBackdrops: false,
+            backgroundOpacity: 1.0,
+            backgroundBlur: .disabled
+        )
+        let policy = snapshot.policy(for: .windowRoot)
+
+        XCTAssertNil(policy.hostLayerBackgroundColor)
+        guard case let .ghosttyTerminalBackdrop(_, _, renderingMode) = policy else {
+            XCTFail("expected terminal backdrop policy")
+            return
+        }
+        XCTAssertEqual(renderingMode, .ghosttyRendererOwnedBackgroundImage)
+    }
+
+    func testTranslucentTerminalBackgroundStaysHostLayerOwned() {
+        let snapshot = makeSnapshot(
+            unifySurfaceBackdrops: false,
+            backgroundOpacity: 0.9,
+            backgroundBlur: .disabled
+        )
+        let policy = snapshot.policy(for: .windowRoot)
+
+        XCTAssertNotNil(policy.hostLayerBackgroundColor)
+        guard case let .ghosttyTerminalBackdrop(_, _, renderingMode) = policy else {
+            XCTFail("expected terminal backdrop policy")
+            return
+        }
+        XCTAssertEqual(renderingMode, .windowHostBackdrop)
+    }
+
+    func testBlurredTerminalBackgroundStaysHostLayerOwned() {
+        let snapshot = makeSnapshot(
+            unifySurfaceBackdrops: false,
+            backgroundOpacity: 1.0,
+            backgroundBlur: .radius(20)
+        )
+        let policy = snapshot.policy(for: .windowRoot)
+
+        XCTAssertNotNil(policy.hostLayerBackgroundColor)
+        guard case let .ghosttyTerminalBackdrop(_, _, renderingMode) = policy else {
+            XCTFail("expected terminal backdrop policy")
+            return
+        }
+        XCTAssertEqual(renderingMode, .windowHostBackdrop)
+    }
+
     func testDebugBackgroundGlassUsesWindowGlassPhase() {
         let snapshot = makeSnapshot(
             unifySurfaceBackdrops: false,
@@ -137,7 +185,10 @@ final class WindowAppearanceSnapshotTests: XCTestCase {
             terminalBackgroundColor: NSColor(hex: "#272822") ?? .black,
             terminalBackgroundOpacity: backgroundOpacity,
             terminalBackgroundBlur: backgroundBlur,
-            terminalRenderingMode: .windowHostBackdrop,
+            terminalRenderingMode: WindowAppearanceSnapshot.terminalRenderingMode(
+                backgroundOpacity: Double(backgroundOpacity),
+                backgroundBlur: backgroundBlur
+            ),
             unifySurfaceBackdrops: unifySurfaceBackdrops,
             sidebarSettings: SidebarBackdropSettingsSnapshot(
                 materialRawValue: SidebarMaterialOption.sidebar.rawValue,