diff --git a/src/renderers/WebGLRenderer.js b/src/renderers/WebGLRenderer.js
index 36a79146db0fc8..4e5e2fa56536d3 100644
--- a/src/renderers/WebGLRenderer.js
+++ b/src/renderers/WebGLRenderer.js
@@ -2129,7 +2129,9 @@ function WebGLRenderer( parameters = {} ) {
 
 		}
 
-		const { width, height, data } = srcTexture.image;
+		const width = sourceBox.max.x - sourceBox.min.x + 1;
+		const height = sourceBox.max.y - sourceBox.min.y + 1;
+		const depth = sourceBox.max.z - sourceBox.min.z + 1;
 		const glFormat = utils.convert( dstTexture.format );
 		const glType = utils.convert( dstTexture.type );
 		let glTarget;
@@ -2161,25 +2163,32 @@ function WebGLRenderer( parameters = {} ) {
 		const unpackSkipRows = _gl.getParameter( _gl.UNPACK_SKIP_ROWS );
 		const unpackSkipImages = _gl.getParameter( _gl.UNPACK_SKIP_IMAGES );
 
-		_gl.pixelStorei( _gl.UNPACK_ROW_LENGTH, width );
-		_gl.pixelStorei( _gl.UNPACK_IMAGE_HEIGHT, height );
+		const image = srcTexture.isCompressedTexture ? srcTexture.mipmaps[ 0 ] : srcTexture.image;
+
+		_gl.pixelStorei( _gl.UNPACK_ROW_LENGTH, image.width );
+		_gl.pixelStorei( _gl.UNPACK_IMAGE_HEIGHT, image.height );
 		_gl.pixelStorei( _gl.UNPACK_SKIP_PIXELS, sourceBox.min.x );
 		_gl.pixelStorei( _gl.UNPACK_SKIP_ROWS, sourceBox.min.y );
 		_gl.pixelStorei( _gl.UNPACK_SKIP_IMAGES, sourceBox.min.z );
 
-		_gl.texSubImage3D(
-			glTarget,
-			level,
-			position.x,
-			position.y,
-			position.z,
-			sourceBox.max.x - sourceBox.min.x + 1,
-			sourceBox.max.y - sourceBox.min.y + 1,
-			sourceBox.max.z - sourceBox.min.z + 1,
-			glFormat,
-			glType,
-			data
-		);
+		if ( srcTexture.isDataTexture || srcTexture.isDataTexture3D ) {
+
+			_gl.texSubImage3D( glTarget, level, position.x, position.y, position.z, width, height, depth, glFormat, glType, image.data );
+
+		} else {
+
+			if ( srcTexture.isCompressedTexture ) {
+
+				console.warn( 'THREE.WebGLRenderer.copyTextureToTexture3D: untested support for compressed srcTexture.' );
+				_gl.compressedTexSubImage3D( glTarget, level, position.x, position.y, position.z, width, height, depth, glFormat, image.data );
+
+			} else {
+
+				_gl.texSubImage3D( glTarget, level, position.x, position.y, position.z, width, height, depth, glFormat, glType, image );
+
+			}
+
+		}
 
 		_gl.pixelStorei( _gl.UNPACK_ROW_LENGTH, unpackRowLen );
 		_gl.pixelStorei( _gl.UNPACK_IMAGE_HEIGHT, unpackImageHeight );