diff --git a/src/CHANGELOG b/src/CHANGELOG
index 33ca32096..e9799f764 100644
--- a/src/CHANGELOG
+++ b/src/CHANGELOG
@@ -921,6 +921,15 @@ ECL 0.6
     libraries. For example, (LOAD (OPEN "foo.lsp")) is equivalent
     to (LOAD "foo.lsp").
 
+  - The arguments of GENSYM should not be remembered by ECLS. The
+    current behaviour is wrong:
+		> (gensym)
+		#:G36
+		> (gensym "F")
+		#:F37
+		> (gensym)
+		#:F38
+
 TODO:
 =====
 
diff --git a/src/c/gbc-new.d b/src/c/gbc-new.d
index 713e860c8..e8a9599c3 100644
--- a/src/c/gbc-new.d
+++ b/src/c/gbc-new.d
@@ -483,8 +483,6 @@ mark_phase(void)
 	    mark_object(clwp->lwp_PRINTcase);
 	    mark_object(clwp->lwp_READtable);
 	    mark_object(clwp->lwp_delimiting_char);
-	    mark_object(clwp->lwp_gensym_prefix);
-	    mark_object(clwp->lwp_gentemp_prefix);
 	    mark_object(clwp->lwp_token);
 
 	    /* (current-thread) can return it at any time
diff --git a/src/c/gbc.d b/src/c/gbc.d
index 7d19b8fe0..2dde37aec 100644
--- a/src/c/gbc.d
+++ b/src/c/gbc.d
@@ -493,8 +493,6 @@ mark_phase(void)
 	    mark_object(clwp->lwp_PRINTcase);
 	    mark_object(clwp->lwp_READtable);
 	    mark_object(clwp->lwp_delimiting_char);
-	    mark_object(clwp->lwp_gensym_prefix);
-	    mark_object(clwp->lwp_gentemp_prefix);
 	    mark_object(clwp->lwp_token);
 
 	    /* (current-thread) can return it at any time
diff --git a/src/c/lwp.d b/src/c/lwp.d
index 9d27e89e6..6ebce8007 100644
--- a/src/c/lwp.d
+++ b/src/c/lwp.d
@@ -151,8 +151,6 @@ make_pd()
   npd->lwp_sharp_eq_context_max = 0;
   
   /* for gc */
-  npd->lwp_gensym_prefix = OBJNULL;
-  npd->lwp_gentemp_prefix = OBJNULL;
   npd->lwp_token = OBJNULL;
     
   /* lex_env copy */
@@ -169,7 +167,6 @@ make_pd()
   npd->lwp_fmt_temporary_string =
     npd->lwp_fmt_temporary_stream->stream.object0;
   
-  npd->lwp_gentemp_prefix = make_simple_string("T");
   npd->lwp_token = cl_alloc_simple_string(LISP_PAGESIZE);
   npd->lwp_token->string.self = cl_alloc_atomic(LISP_PAGESIZE);
   npd->lwp_token->string.fillp = 0;
diff --git a/src/c/symbol.d b/src/c/symbol.d
index 205090c0f..c9a8a2a3b 100644
--- a/src/c/symbol.d
+++ b/src/c/symbol.d
@@ -19,8 +19,6 @@
 /******************************* EXPORTS ******************************/
 
 #ifndef THREADS
-cl_object gensym_prefix;
-cl_object gentemp_prefix;
 cl_object cl_token;
 #endif
 
@@ -30,6 +28,8 @@ cl_object @'si::pname';
 
 /******************************* ------- ******************************/
 
+static cl_object gensym_prefix;
+static cl_object gentemp_prefix;
 static cl_index gentemp_counter;
 
 @(defun make_symbol (str)
@@ -342,21 +342,22 @@ symbol_name(cl_object x)
 	@(return x)
 @)
 
-@(defun gensym (&optional (x gensym_prefix) &aux str)
+@(defun gensym (&optional (prefix gensym_prefix) &aux str)
 	cl_index name_length, j, counter_value;
-	volatile cl_object counter;
+	cl_object counter;
 @
-	if (type_of(x) == t_string) {
-		gensym_prefix = x;
+	if (type_of(prefix) == t_string) {
 		counter = SYM_VAL(@'*gensym-counter*');
-	} else
-		counter = x;
+	} else {
+		counter = prefix;
+		prefix = gensym_prefix;
+	}
 	if (!FIXNUMP(counter) || FIXNUM_MINUSP(counter)) {
 		FEerror("*gensym-counter*, ~A, not a positive fixnum",
 			1, counter);
 	}
 	counter_value = fix(counter);
-	name_length = gensym_prefix->string.fillp;
+	name_length = prefix->string.fillp;
 	for (j = counter_value;  j > 0;  j /= 10)
 		name_length++;
 	if (name_length == 0)
@@ -364,14 +365,15 @@ symbol_name(cl_object x)
 	str = cl_alloc_simple_string(name_length);
 	str->string.self = (char *)cl_alloc_atomic(name_length+1);
 	str->string.self[name_length] = '\0';
-	for (j = 0;  j < gensym_prefix->string.fillp;  j++)
-		str->string.self[j] = gensym_prefix->string.self[j];
+	for (j = 0;  j < prefix->string.fillp;  j++)
+		str->string.self[j] = prefix->string.self[j];
 	if (counter_value == 0)
 		str->string.self[--name_length] = '0';
 	else
 		for (j=counter_value;  j > 0;  j /= 10)
 			str->string.self[--name_length] = j%10 + '0';
-	SYM_VAL(@'*gensym-counter*') = MAKE_FIXNUM(counter_value+1);
+	if (prefix == gensym_prefix)
+		SYM_VAL(@'*gensym-counter*') = MAKE_FIXNUM(counter_value+1);
 	@(return make_symbol(str))
 @)
 
diff --git a/src/h/external.h b/src/h/external.h
index 8dda38fcd..13e63b6df 100644
--- a/src/h/external.h
+++ b/src/h/external.h
@@ -759,9 +759,9 @@ extern void init_structure(void);
 
 /* symbol.c */
 
-extern cl_object gensym_prefix;
-extern cl_object gentemp_prefix;
+#ifndef THREADS
 extern cl_object cl_token;
+#endif
 extern cl_object make_symbol(cl_object st);
 extern cl_object make_ordinary(const char *s);
 extern cl_object make_special(const char *s, cl_object v);
diff --git a/src/h/lwp.h b/src/h/lwp.h
index fa283ade1..c459aa596 100644
--- a/src/h/lwp.h
+++ b/src/h/lwp.h
@@ -136,8 +136,6 @@ typedef struct lpd {
 
   /* symbol.d */
   cl_object lwp_string_register;
-  cl_object lwp_gensym_prefix;
-  cl_object lwp_gentemp_prefix;
   cl_object lwp_token;		/* They have to be initialized with
 			         * alloc_simple_string and */
 } lpd;