diff --git a/src/symbols.c b/src/symbols.c
index dff90870..4635fe60 100644
--- a/src/symbols.c
+++ b/src/symbols.c
@@ -41,7 +41,7 @@ SCM
 init_symbol (SCM x, long type, char const *name)
 {
   TYPE (x) = type;
-  if (!g_symbols)
+  if (g_symbols == 0)
     g_free = g_free + M2_CELL_SIZE;
   else
     {