diff --git a/exec.c b/exec.c
index a77baded2..d1abe5909 100644
--- a/exec.c
+++ b/exec.c
@@ -791,7 +791,7 @@ void exec( job_t *j )
 				int i;
 				string_buffer_t sb;
 				
-				const wchar_t * def = function_get_definition( p->argv[0] );
+				const wchar_t * def = wcsdup(function_get_definition( p->argv[0] ));
 				//fwprintf( stderr, L"run function %ls\n", argv[0] );
 				if( def == 0 )
 				{
@@ -834,6 +834,8 @@ void exec( job_t *j )
 				
 				internal_exec_helper( def, TOP, j->io );
 				
+				free( def );
+
 				parser_allow_function();
 				parser_pop_block();