diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cb85e0bee36..1a44b1777f2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2013-01-15  Richard Biener  <rguenther@suse.de>
+
+	PR bootstrap/55961
+	* system.h: Do not include gmp.h for building host tools.
+
 2013-01-15  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/55882
diff --git a/gcc/system.h b/gcc/system.h
index fbf1f11d85b..41cd565538a 100644
--- a/gcc/system.h
+++ b/gcc/system.h
@@ -636,7 +636,10 @@ extern int vsnprintf(char *, size_t, const char *, va_list);
 #include <dlfcn.h>
 #endif
 
+/* Do not introduce a gmp.h dependency on the build system.  */
+#ifndef GENERATOR_FILE
 #include <gmp.h>
+#endif
 
 /* Get libiberty declarations.  */
 #include "libiberty.h"