diff --git a/conformance/BUILD.bazel b/conformance/BUILD.bazel
index 85b6aa13..df990e88 100644
--- a/conformance/BUILD.bazel
+++ b/conformance/BUILD.bazel
@@ -47,9 +47,6 @@ _TESTS_TO_SKIP = [
     "macros/map/map_extract_keys",
     "timestamps/duration_converters/get_milliseconds",
 
-    # Failing conformance test for unknown reasons
-    "encoders_ext/decode/hello_without_padding",
-
     # Future enhancments.
     "enums/strong_proto2",
     "enums/strong_proto3",
diff --git a/ext/encoders.go b/ext/encoders.go
index 61ac0b77..ac04b1a7 100644
--- a/ext/encoders.go
+++ b/ext/encoders.go
@@ -36,7 +36,7 @@ import (
 // Examples:
 //
 //	base64.decode('aGVsbG8=')  // return b'hello'
-//	base64.decode('aGVsbG8')   // error
+//	base64.decode('aGVsbG8')   // return b'hello'
 //
 // # Base64.Encode
 //
@@ -79,7 +79,14 @@ func (encoderLib) ProgramOptions() []cel.ProgramOption {
 }
 
 func base64DecodeString(str string) ([]byte, error) {
-	return base64.StdEncoding.DecodeString(str)
+	b, err := base64.StdEncoding.DecodeString(str)
+	if err == nil {
+		return b, nil
+	}
+	if _, tryAltEncoding := err.(base64.CorruptInputError); tryAltEncoding {
+		return base64.RawStdEncoding.DecodeString(str)
+	}
+	return nil, err
 }
 
 func base64EncodeBytes(bytes []byte) (string, error) {
diff --git a/ext/encoders_test.go b/ext/encoders_test.go
index 05580192..959cb837 100644
--- a/ext/encoders_test.go
+++ b/ext/encoders_test.go
@@ -29,10 +29,7 @@ func TestEncoders(t *testing.T) {
 		parseOnly bool
 	}{
 		{expr: "base64.decode('aGVsbG8=') == b'hello'"},
-		{
-			expr: "base64.decode('aGVsbG8') == b'error'",
-			err:  "illegal base64 data at input byte 4",
-		},
+		{expr: "base64.decode('aGVsbG8') == b'hello'"},
 		{
 			expr:      "base64.decode(b'aGVsbG8=') == b'hello'",
 			err:       "no such overload",