diff --git a/src/cmd/ksh93/bltins/print.c b/src/cmd/ksh93/bltins/print.c
index 2d51a8b81..443e6c83a 100644
--- a/src/cmd/ksh93/bltins/print.c
+++ b/src/cmd/ksh93/bltins/print.c
@@ -243,11 +243,7 @@ int    b_print(int argc, char *argv[], Shbltin_t *context)
 			break;
 		case ':':
 			/* The following is for backward compatibility */
-#if OPT_VERSION >= 19990123
 			if(strcmp(opt_info.name,"-R")==0)
-#else
-			if(strcmp(opt_info.option,"-R")==0)
-#endif
 			{
 				rflag = 1;
 				if(error_info.errors==0)
diff --git a/src/cmd/ksh93/bltins/typeset.c b/src/cmd/ksh93/bltins/typeset.c
index 21b56953d..52b9c899e 100644
--- a/src/cmd/ksh93/bltins/typeset.c
+++ b/src/cmd/ksh93/bltins/typeset.c
@@ -1043,11 +1043,7 @@ int	b_builtin(int argc,char *argv[],Shbltin_t *context)
 		if(list)
 			sfprintf(sfstdout, "%s %08lu %s\n", arg, ver, path);
 #else
-#if (_AST_VERSION>=20040404)
 		if(!(library = dllplug(SH_ID,arg,NIL(char*),RTLD_LAZY,NIL(char*),0)))
-#else
-		if(!(library = dllfind(arg,NIL(char*),RTLD_LAZY,NIL(char*),0)))
-#endif
 		{
 			errormsg(SH_DICT,ERROR_exit(0),"%s: %s",arg,dlerror());
 			return(1);
diff --git a/src/cmd/ksh93/include/defs.h b/src/cmd/ksh93/include/defs.h
index f30b7dfc1..df5cdfbf6 100644
--- a/src/cmd/ksh93/include/defs.h
+++ b/src/cmd/ksh93/include/defs.h
@@ -29,6 +29,9 @@
 #define defs_h_defined
 
 #include	<ast.h>
+#if !defined(AST_VERSION) || AST_VERSION < 20111111L
+#error libast version 20111111 or later is required
+#endif
 #if !SHOPT_MULTIBYTE
     /* disable multibyte without need for further '#if SHOPT_MULTIBYTE' */
 #   undef mbwide
diff --git a/src/cmd/ksh93/include/fault.h b/src/cmd/ksh93/include/fault.h
index 3e76b22f7..cf0d93fe2 100644
--- a/src/cmd/ksh93/include/fault.h
+++ b/src/cmd/ksh93/include/fault.h
@@ -98,11 +98,7 @@ struct checkpt
 	int		topfd;
 	int		mode;
 	struct openlist	*olist;
-#if (ERROR_VERSION >= 20030214L)
 	Error_context_t err;
-#else
-	struct errorcontext err;
-#endif
 };
 
 #define sh_pushcontext(shp,bp,n)( (bp)->mode=(n) , (bp)->olist=0,  \
diff --git a/src/cmd/ksh93/include/jobs.h b/src/cmd/ksh93/include/jobs.h
index fd780c6ac..93e0ed3a2 100644
--- a/src/cmd/ksh93/include/jobs.h
+++ b/src/cmd/ksh93/include/jobs.h
@@ -118,14 +118,9 @@ extern struct jobs job;
 #ifdef vmlocked
 #define vmbusy()	vmlocked(Vmregion)
 #else
-#if VMALLOC_VERSION >= 20070911L
 #define vmbusy()	(vmstat(0,0)!=0)
 #endif
 #endif
-#endif
-#ifndef vmbusy
-#define vmbusy()	0
-#endif
 
 #define job_lock()	(job.in_critical++)
 #define job_unlock()	\
diff --git a/src/cmd/ksh93/include/streval.h b/src/cmd/ksh93/include/streval.h
index 30008b5de..6e1155fcd 100644
--- a/src/cmd/ksh93/include/streval.h
+++ b/src/cmd/ksh93/include/streval.h
@@ -29,9 +29,7 @@
 #include	<ast.h>
 #include	<math.h>
 #include	"defs.h"
-#if _AST_VERSION >= 20030127L
-#   include	<ast_float.h>
-#endif
+#include	<ast_float.h>
 
 #if _ast_fltmax_double
 #define LDBL_LLONG_MAX		DBL_LLONG_MAX
diff --git a/src/cmd/ksh93/sh/expand.c b/src/cmd/ksh93/sh/expand.c
index bfe33cf80..a9726101c 100644
--- a/src/cmd/ksh93/sh/expand.c
+++ b/src/cmd/ksh93/sh/expand.c
@@ -74,7 +74,6 @@
 
 static struct glob	 *membase;
 
-#if GLOB_VERSION >= 20010916L
 static char *nextdir(glob_t *gp, char *dir)
 {
 	Shell_t	*shp = sh_getinterp();
@@ -88,7 +87,6 @@ static char *nextdir(glob_t *gp, char *dir)
 		return(pp->name);
 	return(0);
 }
-#endif
 
 int path_expand(Shell_t *shp,const char *pattern, struct argnod **arghead)
 {
@@ -108,9 +106,7 @@ int path_expand(Shell_t *shp,const char *pattern, struct argnod **arghead)
 #if KSHELL
 		extra += scantree(shp->alias_tree,pattern,arghead); 
 		extra += scantree(shp->fun_tree,pattern,arghead); 
-#   if GLOB_VERSION >= 20010916L
 		gp->gl_nextdir = nextdir;
-#   endif
 #endif /* KSHELL */
 		flags |= GLOB_COMPLETE;
 		flags &= ~GLOB_NOCHECK;
diff --git a/src/cmd/ksh93/sh/fault.c b/src/cmd/ksh93/sh/fault.c
index 6c7919a28..5d138a23b 100644
--- a/src/cmd/ksh93/sh/fault.c
+++ b/src/cmd/ksh93/sh/fault.c
@@ -45,7 +45,7 @@ static int	cursig = -1;
 #if !_std_malloc
 #   include	<vmalloc.h>
 #endif
-#if  defined(VMFL) && (VMALLOC_VERSION>=20031205L)
+#if  defined(VMFL)
     /*
      * This exception handler is called after vmalloc() unlocks the region
      */
@@ -154,7 +154,7 @@ void	sh_fault(register int sig)
 			shp->trapnote |= SH_SIGSET;
 			if(sig <= shp->gd->sigmax)
 				shp->sigflag[sig] |= SH_SIGSET;
-#if  defined(VMFL) && (VMALLOC_VERSION>=20031205L)
+#if  defined(VMFL)
 			if(abortsig(sig))
 			{
 				/* abort inside malloc, process when malloc returns */
diff --git a/src/cmd/ksh93/sh/init.c b/src/cmd/ksh93/sh/init.c
index f95fc7fb8..51c128e0c 100644
--- a/src/cmd/ksh93/sh/init.c
+++ b/src/cmd/ksh93/sh/init.c
@@ -361,19 +361,11 @@ static void put_cdpath(register Namval_t* np,const char *val,int flags,Namfun_t
      * This function needs to be modified to handle international
      * error message translations
      */
-#if ERROR_VERSION >= 20000101L
     static char* msg_translate(const char* catalog, const char* message)
     {
 	NOT_USED(catalog);
 	return((char*)message);
     }
-#else
-    static char* msg_translate(const char* message, int type)
-    {
-	NOT_USED(type);
-	return((char*)message);
-    }
-#endif
 
     /* Trap for LC_ALL, LC_CTYPE, LC_MESSAGES, LC_COLLATE and LANG */
     static void put_lang(Namval_t* np,const char *val,int flags,Namfun_t *fp)
@@ -467,10 +459,6 @@ static void put_cdpath(register Namval_t* np,const char *val,int flags,Namfun_t
 			sh_lexstates[ST_BRACE]=(char*)sh_lexrstates[ST_BRACE];
 		}
 	}
-#if ERROR_VERSION < 20000101L
-	if(type==LC_ALL || type==LC_MESSAGES)
-		error_info.translate = msg_translate;
-#endif
     }
 #endif /* _hdr_locale */
 
@@ -1243,9 +1231,7 @@ Shell_t *sh_init(register int argc,register char *argv[], Shinit_f userinit)
 	shp->stk = stkstd;
 	sfsetbuf(shp->strbuf,(char*)0,64);
 	sh_onstate(SH_INIT);
-#if ERROR_VERSION >= 20000102L
 	error_info.catalog = e_dict;
-#endif
 #if SHOPT_REGRESS
 	{
 		Opt_t*	nopt;
@@ -1325,17 +1311,8 @@ Shell_t *sh_init(register int argc,register char *argv[], Shinit_f userinit)
 		char *cp=nv_getval(L_ARGNOD);
 		char buff[PATH_MAX+1];
 		shp->gd->shpath = 0;
-#if _AST_VERSION >= 20090202L
 		if((n = pathprog(NiL, buff, sizeof(buff))) > 0 && n <= sizeof(buff))
 			shp->gd->shpath = strdup(buff);
-#else
-		sfprintf(shp->strbuf,"/proc/%d/exe",getpid());
-		if((n=readlink(sfstruse(shp->strbuf),buff,sizeof(buff)-1))>0)
-		{
-			buff[n] = 0;
-			shp->gd->shpath = strdup(buff);
-		}
-#endif
 		else if((cp && (sh_type(cp)&SH_TYPE_SH)) || (argc>0 && strchr(cp= *argv,'/')))
 		{
 			if(*cp=='/')
@@ -1472,11 +1449,9 @@ Shell_t *sh_init(register int argc,register char *argv[], Shinit_f userinit)
 	shp->bltindata.shtrap = sh_trap;
 	shp->bltindata.shexit = sh_exit;
 	shp->bltindata.shbltin = sh_addbuiltin;
-#if _AST_VERSION >= 20080617L
 	shp->bltindata.shgetenv = sh_getenv;
 	shp->bltindata.shsetenv = sh_setenviron;
 	astintercept(&shp->bltindata,1);
-#endif
 #if 0
 #define NV_MKINTTYPE(x,y,z)	nv_mkinttype(#x,sizeof(x),(x)-1<0,(y),(Namdisc_t*)z); 
 	NV_MKINTTYPE(pid_t,"process id",0);
diff --git a/src/cmd/ksh93/sh/lex.c b/src/cmd/ksh93/sh/lex.c
index 54507541c..2aa71a776 100644
--- a/src/cmd/ksh93/sh/lex.c
+++ b/src/cmd/ksh93/sh/lex.c
@@ -2263,15 +2263,7 @@ struct argnod *sh_endword(Shell_t *shp,int mode)
 						break;
 					}
 					*--dp = 0;
-#if ERROR_VERSION >= 20000317L
 					msg = ERROR_translate(0,error_info.id,0,ep);
-#else
-#   if ERROR_VERSION >= 20000101L
-					msg = ERROR_translate(error_info.id,ep);
-#   else
-					msg = ERROR_translate(ep,2);
-#   endif
-#endif
 					n = strlen(msg);
 					dp = ep+n;
 					if(sp-dp <= 1)
diff --git a/src/cmd/ksh93/sh/name.c b/src/cmd/ksh93/sh/name.c
index 278710893..a2db5cd91 100644
--- a/src/cmd/ksh93/sh/name.c
+++ b/src/cmd/ksh93/sh/name.c
@@ -1864,7 +1864,6 @@ void nv_putval(register Namval_t *np, const char *string, int flags)
 			if(sp==up->cp && !(flags&NV_APPEND))
 				return;
 			dot = strlen(sp);
-#if (_AST_VERSION>=20030127L)
 			if(nv_isattr(np,NV_BINARY))
 			{
 				int oldsize = (flags&NV_APPEND)?nv_size(np):0;
@@ -1899,7 +1898,6 @@ void nv_putval(register Namval_t *np, const char *string, int flags)
 				return;
 			}
 			else
-#endif
 			{
 				if(size==0 && nv_isattr(np,NV_HOST)!=NV_HOST &&nv_isattr(np,NV_LJUST|NV_RJUST|NV_ZFILL))
 					nv_setsize(np,size=dot);
@@ -2809,7 +2807,6 @@ char *nv_getval(register Namval_t *np)
 		return(fmtbase(ll,numeric, numeric&&numeric!=10));
 	}
 done:
-#if (_AST_VERSION>=20030127L)
 	/*
 	 * if NV_RAW flag is on, return pointer to binary data 
 	 * otherwise, base64 encode the data and return this string
@@ -2823,7 +2820,6 @@ done:
 		*ep = 0;
 		return(cp);
 	}
-#endif
 	if(!nv_isattr(np,NV_LJUST|NV_RJUST) && (numeric=nv_size(np)) && up->cp && up->cp[numeric])
 	{
 		char *cp = getbuf(numeric+1);
diff --git a/src/cmd/ksh93/sh/path.c b/src/cmd/ksh93/sh/path.c
index d0a7e90bd..5fef2b119 100644
--- a/src/cmd/ksh93/sh/path.c
+++ b/src/cmd/ksh93/sh/path.c
@@ -830,11 +830,7 @@ Pathcomp_t *path_absolute(Shell_t *shp,register const char *name, Pathcomp_t *pp
 				if (dll = dllplugin(SH_ID, stakptr(m), NiL, SH_PLUGIN_VERSION, NiL, RTLD_LAZY, NiL, 0))
 					sh_addlib(shp,dll,stakptr(m),oldpp);
 #else
-#if (_AST_VERSION>=20040404)
 				if (dll = dllplug(SH_ID, stakptr(m), NiL, RTLD_LAZY, NiL, 0))
-#else
-				if (dll = dllfind(stakptr(m), NiL, RTLD_LAZY, NiL, 0))
-#endif
 				{
 					/*
 					 * this detects the 2007-05-11 builtin context change and also
diff --git a/src/cmd/ksh93/sh/string.c b/src/cmd/ksh93/sh/string.c
index 305448e6d..b0d17600c 100644
--- a/src/cmd/ksh93/sh/string.c
+++ b/src/cmd/ksh93/sh/string.c
@@ -703,15 +703,7 @@ char	*sh_fmtqf(const char *string, int single, int fold)
 
 const char *_sh_translate(const char *message)
 {
-#if ERROR_VERSION >= 20000317L
 	return(ERROR_translate(0,0,e_dict,message));
-#else
-#if ERROR_VERSION >= 20000101L
-	return(ERROR_translate(e_dict,message));
-#else
-	return(ERROR_translate(message,1));
-#endif
-#endif
 }
 
 /*
@@ -750,9 +742,7 @@ char *sh_checkid(char *str, char *last)
 	return(last);
 }
 
-#if	_AST_VERSION  <= 20000317L
 char *fmtident(const char *string)
 {
 	return((char*)string);
 }
-#endif
diff --git a/src/cmd/ksh93/sh/subshell.c b/src/cmd/ksh93/sh/subshell.c
index 141b8d8e6..87c7d65b2 100644
--- a/src/cmd/ksh93/sh/subshell.c
+++ b/src/cmd/ksh93/sh/subshell.c
@@ -72,11 +72,7 @@ static struct subshell
 	struct Link	*svar;	/* save shell variable table */
 	Dt_t		*sfun;	/* function scope for subshell */
 	Pathcomp_t	*pathlist; /* for PATH variable */
-#if (ERROR_VERSION >= 20030214L)
 	struct Error_context_s *errcontext;
-#else
-	struct errorcontext *errcontext;
-#endif
 	Shopt_t		options;/* save shell options */
 	pid_t		subpid;	/* child process id */
 	Sfio_t*	saveout;/*saved standard output */