diff --git a/GPU/Common/ReplacedTexture.cpp b/GPU/Common/ReplacedTexture.cpp
index 53668c89c189..d95ee297fbe4 100644
--- a/GPU/Common/ReplacedTexture.cpp
+++ b/GPU/Common/ReplacedTexture.cpp
@@ -513,6 +513,10 @@ ReplacedTexture::LoadLevelResult ReplacedTexture::LoadLevelData(VFSFileReference
 		bool bc = Draw::DataFormatIsBlockCompressed(*pixelFormat, &blockSize);
 		_dbg_assert_(bc || *pixelFormat == Draw::DataFormat::R8G8B8A8_UNORM);
 
+		if (bc && (level.w & 3) != 0 || (level.h & 3) != 0) {
+			WARN_LOG(G3D, "Block compressed replacement texture '%s' not divisible by 4x4 (%dx%d). In D3D11 (only!) we will have to expand (potentially causing glitches).", filename.c_str(), level.w, level.h);
+		}
+
 		data_.resize(numMips);
 
 		basist::ktx2_transcoder_state transcodeState;  // Each thread needs one of these.
@@ -546,6 +550,7 @@ ReplacedTexture::LoadLevelResult ReplacedTexture::LoadLevelData(VFSFileReference
 		}
 		transcoder.clear();
 		vfs_->CloseFile(openFile);
+
 		return LoadLevelResult::DONE;  // don't read more levels
 	} else if (imageType == ReplacedImageType::DDS) {
 		// TODO: Do better with alphaStatus, it's possible.
@@ -562,6 +567,10 @@ ReplacedTexture::LoadLevelResult ReplacedTexture::LoadLevelData(VFSFileReference
 		bool bc = Draw::DataFormatIsBlockCompressed(*pixelFormat, &blockSize);
 		_dbg_assert_(bc);
 
+		if (bc && (level.w & 3) != 0 || (level.h & 3) != 0) {
+			WARN_LOG(G3D, "Block compressed replacement texture '%s' not divisible by 4x4 (%dx%d). In D3D11 (only!) we will have to expand (potentially causing glitches).", filename.c_str(), level.w, level.h);
+		}
+
 		data_.resize(numMips);
 
 		// A DDS File can contain multiple mipmaps.
@@ -583,6 +592,7 @@ ReplacedTexture::LoadLevelResult ReplacedTexture::LoadLevelData(VFSFileReference
 				level.fileRef = nullptr;  // We only provide a fileref on level 0 if we have mipmaps.
 		}
 		vfs_->CloseFile(openFile);
+
 		return LoadLevelResult::DONE;  // don't read more levels
 
 	} else if (imageType == ReplacedImageType::ZIM) {
diff --git a/GPU/Common/TextureReplacer.cpp b/GPU/Common/TextureReplacer.cpp
index da0f94401c17..5e7b471c62ff 100644
--- a/GPU/Common/TextureReplacer.cpp
+++ b/GPU/Common/TextureReplacer.cpp
@@ -337,6 +337,9 @@ bool TextureReplacer::LoadIniValues(IniFile &ini, VFSBackend *dir, bool isOverri
 		}
 	}
 
+	auto gr = GetI18NCategory(I18NCat::GRAPHICS);
+
+	g_OSD.Show(OSDType::MESSAGE_SUCCESS, gr->T("Texture replacement pack activated"));
 	return true;
 }
 
diff --git a/GPU/D3D11/TextureCacheD3D11.cpp b/GPU/D3D11/TextureCacheD3D11.cpp
index d658d19a0106..465981e67379 100644
--- a/GPU/D3D11/TextureCacheD3D11.cpp
+++ b/GPU/D3D11/TextureCacheD3D11.cpp
@@ -348,6 +348,14 @@ void TextureCacheD3D11::BuildTexture(TexCacheEntry *const entry) {
 	if (th > 16384)
 		th = 16384;
 
+	// NOTE: For block-compressed textures, we'll force the size up to the closest 4x4. This is due to an
+	// unfortunate restriction in D3D11 (and early D3D12). We'll warn about it in the log to give texture pack
+	// authors notice to fix it.
+	if (plan.doReplace && Draw::DataFormatIsBlockCompressed(plan.replaced->Format(), nullptr)) {
+		tw = (tw + 3) & ~3;
+		th = (th + 3) & ~3;
+	}
+
 	if (plan.depth == 1) {
 		// We don't yet have mip generation, so clamp the number of levels to the ones we can load directly.
 		levels = std::min(plan.levelsToCreate, plan.levelsToLoad);
diff --git a/assets/lang/en_US.ini b/assets/lang/en_US.ini
index 3462f24c2f0e..7c0999fe1dd3 100644
--- a/assets/lang/en_US.ini
+++ b/assets/lang/en_US.ini
@@ -630,6 +630,7 @@ Stereo rendering = Stereo rendering
 Stretch = Stretch
 Texture Filter = Texture filtering
 Texture Filtering = Texture filtering
+Texture replacement pack activated = Texture replacement pack activated
 Texture Scaling = Texture scaling
 Texture Shader = Texture shader
 Turn off Hardware Tessellation - unsupported = Turn off "hardware tessellation": unsupported