diff --git a/qse/include/qse/cmn/str.h b/qse/include/qse/cmn/str.h
index 57b586c2..29069773 100644
--- a/qse/include/qse/cmn/str.h
+++ b/qse/include/qse/cmn/str.h
@@ -950,6 +950,8 @@ QSE_EXPORT qse_size_t qse_wcsxvfmts (
  *   return buf; 
  * }
  * \endcode
+ *
+ * Double dollars($$) translates a single literal dollar sign. 
  */
 QSE_EXPORT qse_size_t qse_mbsxsubst (
 	qse_mchar_t*           buf,
@@ -1023,6 +1025,8 @@ QSE_EXPORT qse_size_t qse_mbsxnsubst (
  *   return buf; 
  * }
  * \endcode
+ *
+ * Double dollars($$) translates a single literal dollar sign. 
  */
 QSE_EXPORT qse_size_t qse_wcsxsubst (
 	qse_wchar_t*           buf,
diff --git a/qse/lib/cmn/str-subst.h b/qse/lib/cmn/str-subst.h
index 13109656..d37e7676 100644
--- a/qse/lib/cmn/str-subst.h
+++ b/qse/lib/cmn/str-subst.h
@@ -76,7 +76,7 @@ static const char_t* scan_dollar (
 				if (dfl) dfl->len = f - dfl->ptr;
 				return f + 1;
 			}
-			else	f++;
+			else f++;
 		}
 	}
 	else if (*f == T('}')) 
@@ -132,14 +132,7 @@ qse_size_t strxnsubst (
 
 	while (f < fend)
 	{
-		if (*f == T('\\'))
-		{
-			/* get the escaped character and treat it normally.
-			 * if the escaper is the last character, treat it 
-			 * normally also. */
-			if (f < fend - 1) f++;
-		}
-		else if (*f == T('$') && f < fend - 1)
+		if (*f == T('$') && f < fend - 1)
 		{
 			if (*(f + 1) == T('{'))
 			{
@@ -167,7 +160,7 @@ qse_size_t strxnsubst (
 			}
 			else if (*(f + 1) == T('$')) 
 			{
-				/* $$ -> $. \$ is also $. */
+				/* $$ -> $. */
 				f++;
 			}
 		}
diff --git a/qse/samples/cmn/str01.c b/qse/samples/cmn/str01.c
index b7d2fbfa..e3707e4c 100644
--- a/qse/samples/cmn/str01.c
+++ b/qse/samples/cmn/str01.c
@@ -246,8 +246,8 @@ qse_char_t* subst (qse_char_t* buf, qse_size_t bsz, const qse_cstr_t* ident, voi
 		return buf + qse_strxput (buf, bsz, QSE_T("coders"));	
 	}
 
-	/* don't do anything */
-	return buf;
+	/*return buf; returning the buffer pointer will result in empty substitution and the default value won't be used */
+	return QSE_NULL; /* return NULL to take the default value if specified */
 }
 
 static int test13 (void)
@@ -269,6 +269,39 @@ static int test13 (void)
 		}
 		qse_printf (QSE_T("]\n"));
 	}
+
+	qse_char_t buf2[48];
+
+	for (i = 0; i <= QSE_COUNTOF(buf2); i++)
+	{
+		qse_strcpy (buf2, QSE_T("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"));
+		qse_strxsubst (buf2, i, QSE_T("user=${USER},group=${GROUP},xxx=${USERX:=${GROUP:=default value}}"), subst, QSE_NULL);
+		qse_printf (QSE_T("bufsize=%02d, buf2=[%-49s] "), i, buf2);
+
+		qse_printf (QSE_T("["));
+		for (j = 0; j < QSE_COUNTOF(buf2); j++)
+		{
+			if (buf2[j] == QSE_T('\0')) qse_printf (QSE_T("*"));
+			else qse_printf (QSE_T("%c"), buf2[j]);
+		}
+		qse_printf (QSE_T("]\n"));
+	}
+
+	for (i = 0; i <= QSE_COUNTOF(buf2); i++)
+	{
+		qse_strcpy (buf2, QSE_T("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"));
+		qse_strxsubst (buf2, i, QSE_T("user=${USER},group=${GROUP},xxx=${USERX:=${GROUPX:=default value}}"), subst, QSE_NULL);
+		qse_printf (QSE_T("bufsize=%02d, buf2=[%-49s] "), i, buf2);
+
+		qse_printf (QSE_T("["));
+		for (j = 0; j < QSE_COUNTOF(buf2); j++)
+		{
+			if (buf2[j] == QSE_T('\0')) qse_printf (QSE_T("*"));
+			else qse_printf (QSE_T("%c"), buf2[j]);
+		}
+		qse_printf (QSE_T("]\n"));
+	}
+
 	return 0;
 }