diff --git a/configure.ac b/configure.ac
index 4b4aa7ab8..9cf0ddce2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1479,12 +1479,6 @@ AC_CHECK_FUNCS([getpeerucred])
 #
 GNUPG_FUNC_MKDIR_TAKES_ONE_ARG
 
-#
-# Define for regexp support
-#
-AC_DEFINE(DISABLE_REGEX,0, [Define to disable regular expression support])
-
-
 
 #
 # Do we have zlib? Must do it here because Solaris failed
diff --git a/g10/trustdb.c b/g10/trustdb.c
index 64e6ec349..8541cbebc 100644
--- a/g10/trustdb.c
+++ b/g10/trustdb.c
@@ -23,14 +23,10 @@
 #include <stdlib.h>
 #include <string.h>
 
-#ifndef DISABLE_REGEX
-#include <sys/types.h>
-#include <regex.h>
-#endif /* !DISABLE_REGEX */
-
 #include "gpg.h"
 #include "../common/status.h"
 #include "../common/iobuf.h"
+#include "../regexp/jimregexp.h"
 #include "keydb.h"
 #include "../common/util.h"
 #include "options.h"
@@ -1507,7 +1503,6 @@ store_validation_status (ctrl_t ctrl, int depth,
 
 /* Returns a sanitized copy of the regexp (which might be "", but not
    NULL). */
-#ifndef DISABLE_REGEX
 /* Operator characters except '.' and backslash.
    See regex(7) on BSD.  */
 #define REGEXP_OPERATOR_CHARS "^[$()|*+?{"
@@ -1572,7 +1567,6 @@ sanitize_regexp(const char *old)
 
   return new;
 }
-#endif /*!DISABLE_REGEX*/
 
 /* Used by validate_one_keyblock to confirm a regexp within a trust
    signature.  Returns 1 for match, and 0 for no match or regex
@@ -1580,25 +1574,15 @@ sanitize_regexp(const char *old)
 static int
 check_regexp(const char *expr,const char *string)
 {
-#ifdef DISABLE_REGEX
-  (void)expr;
-  (void)string;
-  /* When DISABLE_REGEX is defined, assume all regexps do not
-     match. */
-  return 0;
-#else
   int ret;
   char *regexp;
 
   regexp=sanitize_regexp(expr);
 
-#ifdef __riscos__
-  ret=riscos_check_regexp(expr, string, DBG_TRUST);
-#else
   {
     regex_t pat;
 
-    ret=regcomp(&pat,regexp,REG_ICASE|REG_NOSUB|REG_EXTENDED);
+    ret=regcomp(&pat,regexp,REG_ICASE|REG_EXTENDED);
     if(ret==0)
       {
 	ret=regexec(&pat,string,0,NULL,0);
@@ -1606,7 +1590,6 @@ check_regexp(const char *expr,const char *string)
       }
     ret=(ret==0);
   }
-#endif
 
   if(DBG_TRUST)
     log_debug("regexp '%s' ('%s') on '%s': %s\n",
@@ -1615,7 +1598,6 @@ check_regexp(const char *expr,const char *string)
   xfree(regexp);
 
   return ret;
-#endif
 }
 
 /*