diff --git a/ChangeLog b/ChangeLog
index 5ad577b..34a47bb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -284,6 +284,8 @@ a factor of the size of the compiling workspace (it currently is).
 
 82. Small optimizations in code for finding the minimum matching length.
 
+83. Lock out configuring for EBCDIC with non-8-bit libraries.
+
 
 Version 10.20 30-June-2015
 --------------------------
diff --git a/configure.ac b/configure.ac
index 006b793..ae064fd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -339,13 +339,17 @@ fi
 # Make sure that if enable_ebcdic is set, rebuild_chartables is also enabled.
 # Also check that UTF support is not requested, because PCRE2 cannot handle
 # EBCDIC and UTF in the same build. To do so it would need to use different
-# character constants depending on the mode.
+# character constants depending on the mode. Also, EBCDIC cannot be used with
+# 16-bit and 32-bit libraries.
 #
 if test "x$enable_ebcdic" = "xyes"; then
   enable_rebuild_chartables=yes
   if test "x$enable_unicode" = "xyes"; then
     AC_MSG_ERROR([support for EBCDIC and Unicode cannot be enabled at the same time])
   fi
+  if test "x$enable_pcre2_16" = "xyes" -o "x$enable_pcre2_32" = "xyes"; then
+    AC_MSG_ERROR([EBCDIC support is available only for the 8-bit library]) 
+  fi
 fi
 
 # Check argument to --with-link-size
diff --git a/src/pcre2_internal.h b/src/pcre2_internal.h
index 6c283b9..3c9d954 100644
--- a/src/pcre2_internal.h
+++ b/src/pcre2_internal.h
@@ -39,7 +39,10 @@ POSSIBILITY OF SUCH DAMAGE.
 */
 
 /* We do not support both EBCDIC and Unicode at the same time. The "configure"
-script prevents both being selected, but not everybody uses "configure". */
+script prevents both being selected, but not everybody uses "configure". EBCDIC
+is only supported for the 8-bit library, but the check for this has to be later
+in this file, because the first part is not width-dependent, and is included by
+pcre2test.c with CODE_UNIT_WIDTH == 0. */
 
 #if defined EBCDIC && defined SUPPORT_UNICODE
 #error The use of both EBCDIC and SUPPORT_UNICODE is not supported.
@@ -1803,11 +1806,16 @@ typedef struct pcre2_serialized_data {
 
 #if defined PCRE2_CODE_UNIT_WIDTH && PCRE2_CODE_UNIT_WIDTH != 0
 
+/* EBCDIC is supported only for the 8-bit library. */
+
+#if defined EBCDIC && PCRE2_CODE_UNIT_WIDTH != 8
+#error EBCDIC is not supported for the 16-bit or 32-bit libraries
+#endif
+
 /* This is the largest non-UTF code point. */
 
 #define MAX_NON_UTF_CHAR (0xffffffffU >> (32 - PCRE2_CODE_UNIT_WIDTH))
 
-
 /* Internal shared data tables and variables. These are used by more than one
 of the exported public functions. They have to be "external" in the C sense,
 but are not part of the PCRE2 public API. Although the data for some of them is