diff --git a/Doc/Zsh/compat.yo b/Doc/Zsh/compat.yo
index f1be15fee..d085dfaa7 100644
--- a/Doc/Zsh/compat.yo
+++ b/Doc/Zsh/compat.yo
@@ -19,7 +19,7 @@ tt(argv),
 tt(cdpath),
 tt(fignore),
 tt(fpath),
-tt(HISTCHARS),
+tt(histchars),
 tt(mailpath),
 tt(MANPATH),
 tt(manpath),
@@ -30,6 +30,7 @@ tt(PROMPT2),
 tt(PROMPT3),
 tt(PROMPT4),
 tt(psvar),
+tt(signals),
 tt(status),
 tt(watch).
 
diff --git a/Doc/Zsh/params.yo b/Doc/Zsh/params.yo
index 8daf33d5e..5f772bb50 100644
--- a/Doc/Zsh/params.yo
+++ b/Doc/Zsh/params.yo
@@ -850,7 +850,7 @@ item(tt(SHLVL) <S>)(
 Incremented by one each time a new shell is started.
 )
 vindex(signals)
-item(tt(signals))(
+item(tt(signals) <Z>)(
 An array containing the names of the signals.  Note that with
 the standard zsh numbering of array indices, where the first element
 has index 1, the signals are offset by 1 from the signal number
@@ -1161,7 +1161,7 @@ with the tt(-u) attribute is referenced.  If an executable
 file is found, then it is read and executed in the current environment.
 )
 vindex(histchars)
-item(tt(histchars) <S>)(
+item(tt(histchars) <S> <Z>)(
 Three characters used by the shell's history and lexical analysis
 mechanism.  The first character signals the start of a history
 expansion (default `tt(!)').  The second character signals the
@@ -1173,8 +1173,8 @@ tt(histchars) to characters with a locale-dependent meaning will be
 rejected with an error message.
 )
 vindex(HISTCHARS)
-item(tt(HISTCHARS) <S> <Z>)(
-Same as tt(histchars).  (Deprecated.)
+item(tt(HISTCHARS) <S>)(
+Same as tt(histchars).
 )
 vindex(HISTFILE)
 item(tt(HISTFILE))(
diff --git a/NEWS b/NEWS
index af59cb4e6..9d96ef0d1 100644
--- a/NEWS
+++ b/NEWS
@@ -44,6 +44,10 @@ has not changed, but code such as the following:
 should be changed either to use 'return' instead of 'exit', or to have
 the try/always block outside of any function.
 
+If the shell is invoked as sh or ksh (through a symlink or with the
+'--emulate' option), the 'HISTCHARS' parameter is now available instead
+of 'histchars', and the 'signals' parameter is not initialised.
+
 Changes from 5.6.2 to 5.7.1
 ---------------------------
 
diff --git a/Src/params.c b/Src/params.c
index 863b32600..699dc7ccd 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -309,7 +309,7 @@ IPDEF1("TTYIDLE", ttyidle_gsu, PM_READONLY_SPECIAL),
 #define IPDEF2(A,B,C) {{NULL,A,PM_SCALAR|PM_SPECIAL|C},BR(NULL),GSU(B),0,0,NULL,NULL,NULL,0}
 IPDEF2("USERNAME", username_gsu, PM_DONTIMPORT|PM_RESTRICTED),
 IPDEF2("-", dash_gsu, PM_READONLY_SPECIAL),
-IPDEF2("histchars", histchars_gsu, PM_DONTIMPORT),
+IPDEF2("HISTCHARS", histchars_gsu, PM_DONTIMPORT),
 IPDEF2("HOME", home_gsu, PM_UNSET),
 IPDEF2("TERM", term_gsu, PM_UNSET),
 IPDEF2("TERMINFO", terminfo_gsu, PM_UNSET),
@@ -413,7 +413,7 @@ IPDEF8("MODULE_PATH", &module_path, "module_path", PM_DONTIMPORT|PM_RESTRICTED|P
 
 /* All of these have sh compatible equivalents.                */
 IPDEF1("ARGC", argc_gsu, PM_READONLY_SPECIAL),
-IPDEF2("HISTCHARS", histchars_gsu, PM_DONTIMPORT),
+IPDEF2("histchars", histchars_gsu, PM_DONTIMPORT),
 IPDEF4("status", &lastval),
 IPDEF7("prompt", &prompt),
 IPDEF7("PROMPT", &prompt),
@@ -935,8 +935,10 @@ createparamtable(void)
     setsparam("ZSH_ARGZERO", ztrdup(posixzero));
     setsparam("ZSH_VERSION", ztrdup_metafy(ZSH_VERSION));
     setsparam("ZSH_PATCHLEVEL", ztrdup_metafy(ZSH_PATCHLEVEL));
-    setaparam("signals", sigptr = zalloc((SIGCOUNT+4) * sizeof(char *)));
-    for (t = sigs; (*sigptr++ = ztrdup_metafy(*t++)); );
+    if (!EMULATION(EMULATE_SH|EMULATE_KSH)) {
+	setaparam("signals", sigptr = zalloc((SIGCOUNT+4) * sizeof(char *)));
+	for (t = sigs; (*sigptr++ = ztrdup_metafy(*t++)); );
+    }
 
     noerrs = 0;
 }