diff --git a/expr.c b/expr.c
index 61622b9..6f23f95 100644
--- a/expr.c
+++ b/expr.c
@@ -218,6 +218,7 @@ size_t replaceExpressions(const char* r, char* buffer, size_t buffersize)
     char* w = buffer;
     char* s;
 
+    *w = 0;
     while (*r)
     {
         s = w;
diff --git a/testscript b/testscript
index 19d2c50..d5ff95f 100644
--- a/testscript
+++ b/testscript
@@ -87,3 +87,7 @@ x=-0bla -0.1
 x=-2**2 0-2**2 0+-2**2 0--2**2
 # $(x) should be: 4 -4 4 -4
 
+x=
+y=$(x)
+# <$(x)><$(y)> should be: <><>
+