diff --git a/vlib/compress/deflate/deflate.v b/vlib/compress/deflate/deflate.v
index 87bd3f2e15..e4d399a411 100644
--- a/vlib/compress/deflate/deflate.v
+++ b/vlib/compress/deflate/deflate.v
@@ -3,13 +3,13 @@ module deflate
 import compress as compr
 
 // compresses an array of bytes using deflate and returns the compressed bytes in a new array
-// Example: compressed := deflate.compress(b)?
+// Example: compressed := deflate.compress(b)!
 pub fn compress(data []u8) ![]u8 {
 	return compr.compress(data, 0)
 }
 
 // decompresses an array of bytes using deflate and returns the decompressed bytes in a new array
-// Example: decompressed := deflate.decompress(b)?
+// Example: decompressed := deflate.decompress(b)!
 pub fn decompress(data []u8) ![]u8 {
 	return compr.decompress(data, 0)
 }
diff --git a/vlib/compress/gzip/gzip.v b/vlib/compress/gzip/gzip.v
index fd5c682f25..988314eb4b 100644
--- a/vlib/compress/gzip/gzip.v
+++ b/vlib/compress/gzip/gzip.v
@@ -7,7 +7,7 @@ import compress as compr
 import hash.crc32
 
 // compresses an array of bytes using gzip and returns the compressed bytes in a new array
-// Example: compressed := gzip.compress(b)?
+// Example: compressed := gzip.compress(b)!
 pub fn compress(data []u8) ![]u8 {
 	compressed := compr.compress(data, 0)!
 	// header
@@ -134,7 +134,7 @@ pub fn validate(data []u8, params DecompressParams) !GzipHeader {
 }
 
 // decompresses an array of bytes using zlib and returns the decompressed bytes in a new array
-// Example: decompressed := gzip.decompress(b)?
+// Example: decompressed := gzip.decompress(b)!
 pub fn decompress(data []u8, params DecompressParams) ![]u8 {
 	gzip_header := validate(data, params)!
 	header_length := gzip_header.length
diff --git a/vlib/compress/zlib/zlib.v b/vlib/compress/zlib/zlib.v
index 2967536ceb..3d6f026530 100644
--- a/vlib/compress/zlib/zlib.v
+++ b/vlib/compress/zlib/zlib.v
@@ -3,14 +3,14 @@ module zlib
 import compress as compr
 
 // compresses an array of bytes using zlib and returns the compressed bytes in a new array
-// Example: compressed := zlib.compress(b)?
+// Example: compressed := zlib.compress(b)!
 pub fn compress(data []u8) ![]u8 {
 	// flags = TDEFL_WRITE_ZLIB_HEADER (0x01000)
 	return compr.compress(data, 0x01000)
 }
 
 // decompresses an array of bytes using zlib and returns the decompressed bytes in a new array
-// Example: decompressed := zlib.decompress(b)?
+// Example: decompressed := zlib.decompress(b)!
 pub fn decompress(data []u8) ![]u8 {
 	// flags = TINFL_FLAG_PARSE_ZLIB_HEADER (0x1)
 	return compr.decompress(data, 0x1)